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P J Morgane

Publications and source records attributed to P J Morgane.

At least 37 records · Page 2Linked to original sources
PubMed1992

The primary auditory cortex in cetacean and human brain: a comparative analysis of neurofilament protein-containing pyramidal neurons.

To extend our investigation of the anatomy of sensory systems in highly adapted aquatic and terrestrial mammals, we have analyzed the distribution of a particular population of efferent neurons in the cetacean and human primary auditory cortex using an antibody to non-phosphorylated neurofilament protein (SMI32). The neurofilament protein triplet is differentially distributed within neuronal subpopulations in the primate and cetacean neocortex. In primates, it appears that the somatodendritic domain of a subset of pyramidal neurons furnishing specific corticocortical connections contains high concentrations of neurofilament protein. In the human primary auditory cortex these neurons are located in layers III, V and VI, whereas in cetaceans they are concentrated almost exclusively in the cortical efferent layer IIIc/V. Previous analyses have shown that SMI32 immunoreactivity in the cetacean neocortex is uniformly distributed among functionally different areas, while in human neocortex, the distribution of SMI32-positive neurons exhibit a high degree of regional and laminar specialization that is correlated with the functional and anatomical diversity of the cortical areas. In addition, the overall distribution of SMI32-immunoreactive neurons in the cetacean neocortex is comparable to that observed in paralimbic areas of the human, suggesting that the cetacean neocortex has retained many features of phylogenetically older cortical regions.

Animals↗
PubMed1992

Prenatal protein malnutrition alters behavioral state modulation of inhibition and facilitation in the dentate gyrus.

We have examined the effects of prenatal protein malnutrition on interneuronally mediated inhibition and facilitation in the dentate gyrus of the rat using the paired-pulse technique. Field potentials were recorded in the dentate gyrus in response to paired stimuli delivered to the perforant path. The paired-pulse index (PPI) was used as a measure of the net short-term facilitation or interneuronally mediated inhibition effective at the time of the paired-pulse test and was computed by dividing the amplitude of the second population spike (p2) by the amplitude of the first population spike (p1). PPIs were classified according to p1 in order to compare PPIs between behavioral states and dietary treatments since population spike amplitudes in the dentate gyrus vary in relation to behavioral state. Testing was performed during 4 behavioral states: slow-wave sleep (SWS), paradoxical sleep (REM), immobile waking (IW) and exploratory locomotion (AW) using interpulse intervals (IPI) from 20 to 400 ms. The magnitude and duration of interneuronally mediated inhibition was significantly increased in prenatal protein malnourished animals when compared with controls. Paired-pulse tests performed using an IPI of 20 ms under the high p1 (p1 greater than median) condition showed significantly smaller PPIs in prenatal protein malnourished rats regardless of behavioral state. For IPIs greater than 20 ms PPIs were consistently smaller in prenatal protein malnourished rats during SWS and IW. These data indicate that both the magnitude and duration of interneuronally mediated inhibition are increased in prenatally malnourished rats. No consistent diet-related differences were found during AW and REM using IPIs greater than 20 ms because interneuronally mediated inhibition was relatively suppressed during these behavioral states for both dietary groups. There was no consistent behavioral state modulation of paired-pulse facilitation (IPI = 40 to 80 ms) or late inhibition (IPI = 400 ms) in either diet group. In addition, a new relation between PPI and IPI was found under the low p1 (p1 greater than median) condition. During AW the PPIs observed using IPIs of 40 and 50 ms were smaller than those observed using IPIs of 30 and 60 ms. This depression interrupts what is generally considered the "facilitatory" phase of paired-pulse response and may indicate an interaction between perforant path stimulation and hippocampal theta rhythm which is masked when p1 amplitude is high.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗
PubMed1991

Effects of prenatal protein deprivation on postnatal development of granule cells in the fascia dentata.

The effect of prenatal protein deprivation on the postnatal development of granule cells in the fascia dentata in the rat was studied at 15, 30, 90, and 220 days of age. The granule cells showed a significant reduction in cell size, decreased number of synaptic spines throughout their dendritic extent, and reduced complexity of dendritic branching in the outer two-thirds of the molecular layer. All of these deficits were present at 15 days and persisted throughout the study (220 days). The least deficits in synaptic spine density occurred at 90 days and in dendritic branching at 30 days. Partial restitution of earlier, more severe deficits was associated primarily with maturational events occurring in the protein deprived rats, whereas later increases in deficits were related primarily to a failure of the protein deprived rats to keep pace with neuronal development occurring in the controls. The present results are similar to those noted in our previous study in this journal of the effect of a low protein diet (8% casein) on these neurons that extended from pregnancy until the time of sacrifice at 30, 90, and 220 days of age (Cintra et al., '90; 532:271-277). Taken together, these two studies suggest that the postnatal adaptation of the granule cells to prenatal protein deprivation is primarily due to events that occur during pregnancy and that the site of predilection for the deficit is their dendrites in the outer two-thirds of the molecular layer of the fascia dentata.

Aging↗
PubMed1991

Effects of prenatal protein malnutrition on kindling-induced alterations in dentate granule cell excitability. I. Synaptic transmission measures.

The effects of prenatal protein malnutrition upon the efficacy of excitatory synaptic transmission at the level of the perforant path/dentate granule cell synapse were examined during development of perforant path kindling in chronically implanted adults rats. Rats born to dams fed a low protein (6% casein) or control protein (25% casein) diet were fostered to lactating dams fed the 25% casein diet 24 h after birth and were maintained on this diet throughout life following weaning. Beginning at 90-120 days of age, animals received daily kindling stimulations applied to the perforant path. Extracellular field potentials recorded from the granule cell layer of the dentate gyrus in response to single-pulse stimulation of the perforant path were analyzed to determine the effects of prenatal protein malnutrition on the efficacy of synaptic transmission during the kindling process. Measures used for these analyses included the EPSP slope, an indicator of the level of synaptic drive, the population spike amplitude which is a measure of postsynaptic activation and cellular firing, and the ratio of the population spike amplitude relative to the corresponding EPSP slope value, which was used to evaluate the overall efficacy of synaptic transmission. animals of the 6%/25% diet group were found to have significantly lower afterdischarge thresholds, yet required significantly more daily kindling stimulations to develop generalized motor convulsions (stage 5 seizure) than control animals. Examination of dentate field potentials obtained prior to kindling revealed no significant between group differences in measures of EPSP slope or population spike amplitude. Statistically significant increases in measures of both the population EPSP slope and population spike amplitude were observed in both diet groups 24 h after the first kindled afterdischarge. The degree of increase in both of these measures was significantly greater in animals of the 6%/25% group. Evaluation of input/output measures obtained during kindling revealed a steady increase in the population EPSP slope for both diet groups with animals of the 6%/25% group showing significantly greater levels of enhancement in this measure than controls. Enhancement of population spike amplitudes reached maximal values in animals of the 25%/25% group within the first few kindling stimulations and these levels remained unchanged until the first stage 5 seizure. In contrast, animals of the 6%/25% group showed a continuous increase in the population spike amplitude measure during the entire kindling process. Appearance of the first generalized motor convulsion (stage 5 seizure) resulted in a decrease in population spike amplitudes in both diet groups, with animals of the 6%/25% group showing a significantly greater decrease in this measure than controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Aging↗
PubMed1991

Effects of prenatal protein malnutrition on kindling-induced alterations in dentate granule cell excitability. II. Paired-pulse measures.

The effects of prenatal protein malnutrition on kindling-induced changes in inhibitory modulation of dentate granule cell activity were examined by analysis of extracellular field potentials recorded from the granule cell layer of the dentate gyrus in response to paired-pulse stimulation of the perforant pathway in freely-moving rats. Since we have shown that kindling results in enhanced synaptic transmission at the level of the perforant path/granule cell synapse (see preceding paper), we sought to determine if the kindling process might induce changes in inhibitory modulation of granule cell excitability which could be involved in the slower acquisition of the kindled state we have previously reported in malnourished animals. Beginning at 120-150 days of age, the response of dentate granule cells to paired-pulse stimulation of the perforant path was examined at interpulse intervals (IPIs) ranging from 20-1000 ms. A paired-pulse index (PPI) was constructed based on the mean percent change in population spike amplitudes of the two responses resulting from application of the pulse pair. PPI measures obtained during the kindling process were compared with individual prekindling measures to determine the mean percent change in excitatory/inhibitory modulation of granule cell activity. Significant inhibition of the second population response was apparent at all IPIs tested for both diet groups following the first kindled afterdischarge.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1991

Prenatal protein malnutrition and hippocampal function: rapid kindling.

A stimulation paradigm evoking rapidly recurring seizure activity from the hippocampal dentate gyrus was used to examine perforant path kindling in prenatally protein malnourished adult rats. Biphasic electrical stimulations (50 Hz) of five s duration were applied to the perforant path every five min for one hour over five consecutive days. Behavioral manifestations of seizure activity were assessed using the standard 0-5 scale. Prenatally malnourished rats exhibited significantly fewer convulsive seizures (stage 5) and required significantly more stimulations to attain the first stage 5 seizure than controls. Animals of the malnourished group also exhibited significantly more stage 1 seizures than control animals, indicating a significant retardation in the kindling rate of these animals. Additionally, 3 of the 11 malnourished animals failed to exhibit a single stage 5 seizure during the 60 stimulation test period. These findings parallel previous results reported for prenatally protein malnourished rats using the traditional one stimulation-per-day kindling paradigm and indicate that this rapid kindling paradigm can be effectively used to study the impact of various insults on seizure susceptibility and development in a shortened time frame.

Analysis of Variance↗
PubMed1990

Effects of protein undernutrition on the dentate gyrus in rats of three age groups.

The effect of an 8% casein and a control 25% casein diet on the granule cells in the dorsal blade of the dentate gyrus of the rat hippocampal formation was studied at 30, 90 and 220 days of age. Female rats were fed either an 8% or 25% casein diet 5 weeks prior to conception and the litters were maintained on these respective diets until killed. In rapid-Golgi-impregnated cells, we measured major and minor axes of the soma of the dentate granule neurons, the number of spines on 50-microns segments of proximal, middle and terminal regions of the largest dendrite per granule cell and the number of dendrites intersecting 8 concentric rings 38 microns apart. At all 3 ages studied undernourished rats showed, when compared to controls, significant reductions of the major and minor axes of the somata and significant reductions in the number of spines on dendrites in the middle and terminal dendritic segments. Dendritic branching was significantly reduced in undernourished rats compared to controls in all but the 4th concentric rings, with the greatest effect being seen on the outer 3 concentric rings at 90 and 220 days of age. The location of the deficit in dendritic synaptic spines and the greatest deficit in dendritic branching correspond to the sites of termination of the lateral and medial perforant pathway projection to the dentate gyrus on the terminal and middle dendritic segments of the granule cells. The deficits noted in the granule cells of the dentate gyrus in this study were more severe than those found in our previous studies on the effect of the low protein diet in these same rats on visual cortical pyramidal cells and on the 3 cell types in the nucleus raphe dorsalis and nucleus locus coeruleus.

Analysis of Variance↗
PubMed1990

Effects of prenatal protein malnutrition on perforant path kindling in the rat.

Rats born to dams fed either a 6% (malnourished) or 25% (control) casein diet during gestation were all fostered to lactating dams on the 25% casein diet 24 h after birth and were maintained on this diet throughout life following weaning. At 90-120 days of age electrographic and behavioral responses to electrical kindling of the medial perforant pathway were investigated in animals from both the straight 25% diet (designated 25%/25% for the pre- and postnatal periods) and the dietary rehabilitated (designated 6%/25% casein diet for the pre- and postnatal periods) groups. Animals of the dietary rehabilitated group (6%/25%) were found to: (1) require a significantly lower stimulus intensity to evoke afterdischarge activity in the ipsilateral dentate gyrus; (2) progress through the various behavioral stages of kindling in a markedly different manner from the 25%/25% group, and; (3) require significantly more daily kindling stimulations to attain the full motor convulsive stage indicative of the kindled state. These results indicate that dietary protein rehabilitation at birth is incapable of reversing or significantly ameliorating the effects of gestational protein deficiency on susceptibility to seizure activity and acquisition of the kindled state. These findings indicate that gestational protein deficiency results in long-lasting, if not permanent, changes in neuronal systems in the hippocampal formation which are involved in both the electrographic and behavioral correlates of the kindling process.

Animals↗
PubMed1990

Effects of protein deprivation on pyramidal cells of the visual cortex in rats of three age groups.

The effect of protein deprivation on rapid Golgi impregnated pyramidal neurons in layers II/III and V of the rat visual cortex was studied at 30, 90, and 220 days of age using morphometric methods. In order to mimic human under-nutrition female rats were adapted to either an 8% or control 25% casein diet 5 weeks prior to conception and maintained on these diets during gestation and lactation. The pups were then weaned and maintained on their respective diets. The undernourished rats showed a significant decrease in brain weight only at 90 days, indicating that the protein deprivation had a mild effect on brain development. Correspondingly, the number of significant histological differences between the two diet groups were least at 30 and 220 days of age. The effect of the diet was greater on layer V than on layer II/III pyramids. At 30 days of age the effect of the diet was different on the pyramids of these two cell layers, at 90 days there was a mixture of similar and dissimilar effects, and at 220 days the pyramids of these two cell layers showed only minor differences between the two diet groups. Analysis of age-related changes indicated that the effect of the diet was different on layer II/III pyramids compared to layer V pyramidal cells. These different effects apparently accounted for the progression from a dissimilar effect of the diet at 30 days on the pyramids of the two cell layers to only minor differences between them at 220 days. Further analysis of these age-related changes shows that two prominent effects of protein deprivation are for age-related changes to occur in undernourished rats but not in controls and for age-related changes to be out-of-phase with each other in the two diet groups. From these findings, and a review of similar studies in the literature, we propose that these mechanisms are a prominent effect of undernutrition in the post-weaning period and help account for the unexpected increases in morphometric measurements noted in undernourished rats in this and other studies.

Aging↗
PubMed1990

Ultrastructure of synapses and golgi analysis of neurons in neocortex of the lateral gyrus (visual cortex) of the dolphin and pilot whale.

Qualitative and computerized quantitative analyses of ultrastructural features of synapses in different layers of the primary visual cortex in the dolphin (Stenella coeruleoalba) and the pilot whale (Globicephala melaena) were carried out. Also, Golgi and cytoarchitectonic analyses were performed in the same species of cetaceans and, additionally, in Tursiops truncatus and Phocaena phocaena. It was found that on a synaptic level, as well as in cytoarchitectonic and Golgi features, the neocortex of cetaceans combines evolutionary progressive features and conservative features with a marked prevalence of the latter. Thus, the total number of synapses in visual neocortex in cetaceans is closer to this value in higher Primates. On the other hand, the laminar density of synapses per mm3 is generally the same in all layers in cetacean visual cortex and numerically is close to values found in small lissencephalic brains. Also, the synapse/neuron ratio in the dolphin visual cortex is of the same order as in cortices of rodents and lagomorphs and much higher than in cortices of advanced terrestrial mammals. Layers I and II contain approximately 70% of the total synapses in the cortical slab through visual cortex. Layer I also contains the extraverted dendrites of neurons of layer II and thus these two layers resemble a paleoarchicortical type of organization superimposed on a more typical neocortical organization of the lower cortical layers. In this respect the convexity neocortex of cetaceans is generally similar to the neocortices of phylogenetically ancient extant mammals such as basal Insectivora and Chiroptera.

Animals↗
PubMed1989

Paired-pulse facilitation and inhibition in the dentate gyrus is dependent on behavioral state.

It is well established that neuronal transmission from the entorhinal cortex through the dentate gyrus via the perforant path is dependent on behavioral state. To further study the modulation of neuronal transmission by behavioral state we employed the paired-pulse technique to study interneuronally-mediated inhibition and short-term facilitation in the dentate gyrus of freely-moving rat preparations. Precisely timed double pulses of electrical stimulation were delivered to the perforant path in the chronically implanted rat preparation during each of four well-defined behavioral states: slow-wave sleep (SWS), REM sleep (REM), immobile waking (IW) or active waking with voluntary movements (AW). Evoked field potentials were recorded in the dentate gyrus and analyzed to measure the population spike amplitude which represents the total number of dentate granule cells firing in synchronous response to perforant path stimulation. The paired-pulse index (PPI) was used as a measure of the net short-term facilitation or interneuronally-mediated inhibition effective at the time of the paired-pulse test and is computed by dividing the amplitude of the second population spike (p2) by the amplitude of the first population spike (p1). During the course of this study 3754 paired-pulse tests were performed in 9 rat preparations. The three interpulse interval (IPI) values used in these studies were 25, 30 and 35 ms. The results showed that the PPI was greater during AW and REM as compared to SWS and IW. The PPI was significantly greater during AW than during SWS and IW regardless of p1 amplitude or IPI value. The PPI was significantly greater during AW than during REM under most conditions except those corresponding to low p1 amplitude and long IPI. The PPIs measured during REM were significantly greater than those measured during SWS and IW at short IPIs (25 and 30 ms) but not at an IPI of 35 ms. These results indicate that short-term facilitation is the dominant response during AW especially when observed using an IPI of 35 ms. In contrast, interneuronally-mediated inhibition was observed to be dominant during SWS and IW. The net effect during REM was observed to lie between these two extremes using an IPI of 25 ms and tended toward short-term facilitation at longer IPIs of 30 and 35 ms. Septal disinhibition of dentate granule cells is proposed as the mechanism for this effect. The behavioral state modulation of neuronal transmission through the dentate gyrus is discussed in terms of this hypothesis.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗
PubMed1989

Effects of dietary protein on food and water intake in spontaneously hypertensive rats.

We have been studying the development of hypertension in spontaneously hypertensive rats (SHR) fed a low protein diet. The effects of a low protein diet upon food and water intake were examined. Body weight gain, food and water intake were measured in three to twenty-three week-old SHR and Wistar Kyoto rats (WKY) fed diets containing 8%, 15% or 25% casein. Body weights of SHR and WKY fed an 8% casein diet were significantly lower at 23 weeks than rats on the higher protein diets, although both groups on the 8% diet consumed more food and water per g of body weight. In addition, SHR fed an 8% casein diet drank less water per gram of food than WKY or SHR fed 15% and 25% casein diets. These results indicate that changes in food and water intake, as a consequence of low protein diets, should be an additional consideration when examining the effects of dietary protein on the development of hypertension.

Animals↗
PubMed1988

Visual cortex of the dolphin: an image analysis study.

On cytoarchitectonic grounds we have identified two distinct types of cortical formations composing the lateral gyrus (visual cortex) of the dolphin and have termed these heterolaminar cortex and homolaminar cortex. The heterolaminar cortex occupies the medial and lateral banks of the entolateral sulcus whereas the homolaminar cortex occupies the remainder of the lateral gyrus both lateral and medial to the entolateral sulcus. Each of these cortices exhibits special cytoarchitectonic features, a major difference being that heterolaminar cortex contains an incipient layer IV whereas layer IV is clearly absent in homolaminar cortex. Quantitative imaging procedures reveal that there is greater laminar differentiation in heterolaminar than in homolaminar cortex. Golgi analysis of neuronal forms and dendritic architecture confirms this distinction between the two types of cortex composing the lateral gyrus. Computer-assisted morphometric methods have been applied to both types of cortex and indicate by a variety of parameters several quantitative differences in the cellular numbers, types, and organization in each type of cortex. Both types of cortex, homolaminar and heterolaminar, exhibit a markedly higher cellular density in the posterior sector of the lateral gyrus than in the anterior sector. We have also for the first time been able to identify a columnar type of organization of the cetacean visual cortex and have described two types of cytoarchitectonic columns, major and minor, in each of these types of cortex. Comparisons in organization of these basic columnar units between the bat, representing a prototypic brain, and the dolphin reveal many similarities but also major quantitative differences in type of organization between the visual cortices in these species. Marked differences are also seen between the cytoarchitectonic columnar organization of the visual cortices in the dolphin and columnar organization of striate cortex in the human brain, the number of columns per unit of cortex in the human being almost twice that seen in the dolphin brain. Some phylogenetic implications of these findings are discussed in relation to the so-called "initial" type of cortical organization reconstructed largely by retrospective inference.

Aging↗
PubMed1987

Ultrastructure of the blood-brain barrier in the dolphin (Stenella coeruleoalba).

Light and electron microscopic methods were used for investigation of angioarchitectonics, glioarchitectonics and the structural basis of the blood-brain barrier in the dolphin Stenella coeruleoalba. It was shown that the cortical plate of the dolphin brain is extremely rich in capillaries and small arteries that are organized into a complicated net of continuous loops surrounding neuronal groups. The density of the capillary loops is related to the cytoarchitectural density of the cortex. It was also found that the neuronal microenvironment in the dolphin cortex is characterized by the presence of a large number of the astroglia-like cells that make a multi-layered investment surrounding capillaries and small arteries. These glial cells, unlike typical astrocytes of terrestrial mammals, have a large number of different organelles and their nuclei are similar to those of the oligocytes. The ultrastructure of the blood-brain barrier in the dolphin is characterized by the presence of extremely long tight junctions between endothelial cells and by specialized junctions between pericapillary astroglia-like cells. A belt of the glial end-feet interlocked with different types of junctions such as zonulae adherentes, maculae adherentes and gap junctions was found around all investigated capillaries. This system of specialized interendothelial and glio-glial junctions is tentatively hypothesized to be a feature of adaptation of the dolphin to the aquatic environment.

Animals↗
PubMed1987

Effects of pre- and early postnatal protein malnutrition on carcass composition and lipoprotein lipase activity in male rats.

Little is known about the effects of pre- and early postnatal protein malnutrition on energy storage (e.g., carcass lipid) and expenditure (e.g., brown adipose tissue [BAT] thermogenesis) and their reversibility by nutritional rehabilitation. Therefore, the purpose of these experiments was to examine the permanence of prenatal and early postnatal protein malnutrition on energy balance in rats. Five weeks before mating and through gestation adult female rats were fed either a 25 or 8% casein diet (designated 25 or 8). Diet reversals were performed at birth and/or at weaning (designated B or W) and the pups were cross-fostered at birth. Thus, the groups were: 25-25B (controls), 8-25W (gestational and lactational protein malnutrition, 8-25B (gestational protein malnutrition), and 25-8B-25W (lactational protein malnutrition). Animals were weighed and sacrificed 200-250 days postpartum for carcass composition. Retroperitoneal white adipose tissue (RWAT) and interscapular BAT (IBAT) wet weights and lipoprotein lipase (LPL) activity were also measured in the 25-25B and 8-25W groups. Nutritional rehabilitation at birth (8-25B) resulted in normal body weights as adults. Lactational protein malnutrition (25-8B-25W) resulted in intermediate body weights to the controls (25-25W), which had the greatest weights, and the 8-25W group, which had the lowest weights. The 8-25W and 25-8B-25W rats also had significantly decreased carcass wet weight and total body water, fat and fat-free dry mass relative to the 25-25B and 8-25B groups, the latter two of which did not differ in their carcass composition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1987

Spectral analysis of the electroencephalogram in the developing rat.

Power spectral measures of the EEG obtained from the frontal cortex and hippocampal formation during different vigilance states in the developing rat have been computed and compared. The most significant ontogenetic changes were observed in the hippocampal power spectra obtained during the vigilance state of REM sleep. These spectral analyses have revealed in the hippocampus: (1) a significant increase in the frequency at which the peak power occurs in the theta-frequency (4-11 Hz) band from 14 to 45 days of age; (2) a decrease in the quality factor of the peak from 14 to 45 days of age; (3) a decrease in the relative power co-ordinate for the center of spectral mass associated with the 0-4-Hz frequency band coupled with an increase in the frequency coordinate of the 4-11-Hz frequency band from 14 to 45 days of age, and; (4) a significant decrease in the average percent relative power associated with the 0-4-Hz frequency band from 14 to 22 days of age. For the EEG obtained from the frontal cortex, the major findings of note were: (1) a dominant contribution of relative power in the 0-4-Hz frequency band which was observed at every age and during every vigilance state tested, and; (2) a significant increase in the average percent relative power associated with this band at 18, 22, and 45 days of age. The results of this study provide a quantitative description of the electroencephalographic (EEG) ontogeny of the hippocampal formation and the frontal cortex in the rat. These ontogenetic changes in EEG activity relate closely to development of the internal circuitry and synaptic maturation in the hippocampal formation and frontal cortex.

Aging↗
PubMed1986

Effect of protein malnutrition on hippocampal kindling: electrographic and behavioral measures.

Rats born to dams fed either a 6% (malnourished) or a 25% (control) casein diet during gestation and lactation and maintained on the diet of the dam after weaning were tested for electrographic and behavioral responses to electrically induced kindling of the CA1 field of the hippocampus beginning at 44 days of age. Animals in the 6% diet group had a significantly lower threshold to afterdischarge (AD), a significantly faster spread of AD activity to distal recording sites, significantly longer average duration of AD activity at all recording sites and a markedly altered behavioral progression toward seizure activity compared to control animals. These findings indicate that prenatal protein malnutrition results in hippocampal dysfunction as evidenced by both the electrographic and behavioral correlates of the kindling process. The data presented suggest that prenatal proteins malnutrition alters the response of hippocampal CA1 pyramids to electrical stimulation and that this alteration results in marked changes to both the electrographic and behavioral correlates of kindling.

Animals↗