Search PubMed⌕ Search

Biomedical subjects

F C Barone

Publications and source records attributed to F C Barone.

At least 127 records · Page 7Linked to original sources
PubMed1981

Effects of ventral tegmental area stimulation and microiontophoretic application of dopamine and norepinephrine on hypothalamic neurons.

The effects of ventral tegmental area of Tsai (VTA) stimulation on lateral hypothalamic (LH), lateral preoptic area (LPA). and medial hypothalamic neuronal activity were determined in anesthetized rats. Recordings from 81 hypothalamic neurons indicate that stimulation produces predominantly decreases in hypothalamic neuron activity. Increase in activity due to VTA stimulation occurred less frequently. Following single rectangular pulse stimulation, 0.5 msec. 0-500 microA, short latency decreases in activity occurred. Longer latency increases in discharge frequency were also observed. Dose response relations were established for 56% of the LH neurons, 78% of the LPA neurons, and for 82% of the medial hypothalamic neurons following VTA stimulation. Decreases and in a few cases increases in activity seemed to involve only one or two synapses. Antidromic responses verified interconnections between the VTA and the hypothalamus and revealed relatively slow conduction velocities of 0.45 and 0.81 m/sec. The changes in discharge frequency which occurred following VTA stimulation were similar in direction to the effects of the direct microiontophoretic application of dopamine (DA) or norepinephrine (NE). Since DA increased or decreased while NE decreased discharge frequency, these microiontophoretic tests indicated that the shorter latency VTA stimulation induced increases in decreases in neural activity were associated with VTA dopaminergic neuron stimulation and that in some cases short and long latency decreases in neuronal activity were due to activation of VTA ventral bundle NE fibers of passage or to indirect polysynaptic mechanisms. Results demonstrate the interconnections between various regions of the hypothalamus and the VTA along the extent of the medial forebrain bundle (MFB). The cross-validation of neuroanatomical and various electrophysiological methods in establishing the nature of hypothalamic connections was discussed.

Animals↗
PubMed1981

Effects of periaqueductal gray stimulation of diencephalic neural activity.

The effects of ipsilateral mesencephalic periaqueductal gray (PAG) stimulation on lateral hypothalamic (LH), lateral preoptic area (LPA), and ventral and subthalamic activity were determined in anesthetized rats. Recordings from 119 diencephalic neurons indicate that the PAG provides a predominantly inhibitory input to diencephalic neurons. Excitatory input occurred infrequently in the hypothalamus and was not observed in the thalamus. Following single rectangular pulse stimulation, 0.5 msec, 0-500 micro A, short latency decreases in activity occurred. Longer latency increases in discharge frequency were also observed. Dose response relations were established for 74% of the LH neurons, 68% of the LPA neurons, and for 72% of the ventral and subthalamic neurons following VTA stimulation. Decreases and, in a few hypothalamic neurons, increases in activity seemed to involve only one or two synapses. The effects of contralateral PAG stimulation on LPA-LH neuronal activity were alos determined. Dose response relations were established for 66% of the LPA-LH neurons following contralateral stimulation. However, results were different in that many more cells were increased with a shorter latency and at a lower threshold following contralateral stimulation. Antidromic responses verified PAG and diencephalic interconnections and revealed relatively slow conduction velocities, less than 1.0 m/sec. Results were discussed in terms of the anatomy of known PAG pathways, PAG neuronal activation vs. PAG fibers of passage, and the functions of midbrain-hypothalamic interconnections in the integration of somatic, visceral and nociceptive sensory inputs.

Animals↗
PubMed1981

Afferent connections to the lateral hypothalamus: a horseradish peroxidase study in the rat.

Horseradish peroxidase, 13% Sigma Type VI, was administered iontophoretically to the mid lateral hypothalamus (LH) of male hooded rats. Animals were perfused intracardially on the following day and brains were removed and sliced in the coronal or sagittal planes into 30-50 micrometer sections. Sections were processed with DAB and BDH for the brown and blue reaction products and later examined by bright and dark field microscopy for the presence and location of retrogradely labeled neurons. Results indicate that a significant number of afferent connections to the LH originate in the olfactory and accumbens nuclei, pyriform cortex, olfactory tracts, magnocellular and medial preoptic and anterior hypothalamic regions, stria terminalis, stria hypothalamic tract, diagonal tract of Broca, caudate-putamen and globus pallidus, internal capsule, lateral septal nuclei, lateral preoptic area and anterior medial forebrain bundle, the various amygdaloid nuclei, zona incerta, perifornical region, dorsal and ventral medial hypothalamic areas, supraoptic, paraventricular and periventricular nuclei, posterior hypothalamus and medial forebrain bundle, ventral thalamic nuclei, the fields of Forel, arcuate and mammillary nuclei, adjacent to the fasciculus retroflexus, in the ventral tegmental area of Tsai, interpeduncular nucleus, substantia nigra, mesencephalic reticular formation, periaqueductal gray, locus coeruleus and parabrachial region. Results are discussed in terms of previous anatomical and neurophysiological data, probable pathways, and the function of LH neurons.

Afferent Pathways↗
PubMed1980

The effects of several barbiturates on lithium chloride induced taste aversion.

The effects of single doses of five barbiturates on LiCl induced saccharin aversion were examined. Twenty three hour fluid deprived rats were offered a novel 0.125% saccharin solution and then were injected with either 3.0 mEq/kg LiCl or 0.9% saline. On the first test day after conditioning the animals were injected with either 60 mg/kg sodium phenobarbital, 80 mg/kg sodium barbital, 30 mg/kg sodium amobarbital, 20 mg/kg sodium secobarbital, 9 mg/kg sodium pentobarbital or 0.9% saline, 15 min prior to the drinking session. Results indicate that only 9 mg/kg pentobarbital, 60 mg/kg phenobarbital, and 80 mg/kg barbital were effective in attenuating the LiCl induced saccharin aversion on the day of administration. In addition, dipsogenic effects for only 60 mg/kg phenobarbital and 30 mg/kg amobarbital were observed in the saline treated control groups. A synergistic interaction between the effects of LiCl and sodium phenobarbital, barbital, and secobarbital was also observed. Lithium chloride plus these barbiturates resulted in a longer term aversion to saccharin than LiCl alone and no barbiturate produced saccharin aversion when administered without LiCl.

Animals↗
PubMed1980

The taste aversion induction properties of two long duration barbiturates.

The ability of sodium phenobarbital (60 mg/kg) and sodium barbital (80 mg/kg) to produce a taste aversion in 23 hr fluid deprived rats was examined using a discrimination or two bottle taste aversion task (0.125% sodium saccharin solution or water). The interaction of both barbiturates with the effects of 3.0 mEq/kg lithium chloride (LiCl) was also examined. Results indicate that phenobarbital treatment alone produces a stronger saccharin aversion than does barbital. Also, barbiturate treatment 24 hr after LICi administration does not attenuate saccharin avoidance, although phenobarbital treatment following LiCl administration was sufficient to induce a maximum aversion that did not extinguish after twenty days of continuous discrimination testing. These data suggest that the aversion inducing properties of the two barbiturates are dissimilar and that phenobarbital is the more effective agent in the production of saccharin aversion. In addition, barbiturate induced attenuation of conditioned taste aversion is apparently related to the periodic forced intake test model since it does not occur when a water and saccharin choice is available.

Animals↗
PubMed1979

Effects of caffeine on FT-1 min schedule induced drinking at different body weights.

The effects of caffeine (3.125, 6.25, 12.5, 25.0, 50.0, and 100.0 mg/kg) on lever pressing, schedule induced licking, and water consumption induced by a fixed time 1 min schedule of food reinforcement were studied. Changes in these dependent variables were assessed when animals were reduced to 80% of their initial body weight by partial food deprivation and when body weight recovered after the animals were returned to conditions of ad lib feeding. Results indicate similar decreases in licking and drinking at the highest doses of caffeine under both feeding and body weight conditions. The results were compared to previous research which evaluated the effects of caffeine on adjunctive behavior.

Animals↗
PubMed1978

Effects of ethyl alcohol on forced consumption of an acclimated saline solution.

Forced consumption of a 1.7% sodium chloride solution was determined in 3 groups of male hooded rats, 4 in each group, over a period of 115 days. A control group received 1.7% NaCl for the duration of the experiment. An ethyl alcohol experimental group received gradually increasing concentrations of ethyl alcohol, 0.5 to 6.0%, in the 1.7% NaCl drinking fluid for 30 days. For the next 25 days 6% ethanol was mixed with the 1.7% sodium chloride solution. A second experimental group was treated similarly except that varying concentrations of citric acid were added to the saline drinking fluid in place of the ethyl alcohol. At the end of the 55 day period, the ethyl alcohol and citric acid were removed from the drinking fluid of both groups. Dramatic and copious amounts of drinking occurred only in the group which had previously drunk the ethyl alcohol. Since excessive drinking of the 1.7% sodium chloride solution did not occur in the other experimental group when the citric acid was removed, the copious drinking can be attributed specifically to the prolonged ingestion and withdrawal of the ethyl alcohol. Possible significance to an animal model for alcoholism is discussed.

Alcoholism↗
PubMed1976

Effects of acute and chronic administration of caffeine on schedule dependent and schedule induced behavior.

The effects of caffeine (3.125, 6.25, 12.5, 25, 50, and 100 mg/kg) on lever pressing, schedule induced licking and water consumption induced by a fixed interval 1 min schedule were studied. Changes in these dependent variables were assessed when animals were reduced to 80% of their initial body weight by partial food deprivation and when body weights recovered after the animals were returned to conditions of ad lib feeding. Results indicate differential effects of the drug between animals at 80% body weight and when they are permitted to recover. Tolerance was examined for a single large dose only for the same dependent variables in animals at 80% body weight.

Animals↗
PubMed1976

Effects of angiotensin on drinking.

A series of four experiments was carried out to assess the effects of angiotensin II on drinking elicited by various types of stimulation. Experimental I examined the effects of the interaction of 2 cc/kg of 5% NaCl plus 0.2 mg/kg angiotensin II on ad lib eating and drinking. Results indicate that NaCl plus angiotensin produced an additive enhancement in water consumption. Experiment 2 was conducted to investigate the effects of 0.2, 0.4, 0.8, 1.2, and 1.6 mg/kg of angiotensin II on drinking and eating in 23 hr water deprived animals. Dose related increases in drinking alone were observed. In Experiment 3 the effects of 0.4, 0.8, 1.2, and 1.6 mg/kg of angiotensin II on schedule dependent lever pressing and schedule induced drinking and licking were determined. Results demonstrate that angiotensin II decreased lever pressing and increased schedule induced water consumption without a concomitant increase in licking. Experimental 4 examined the effects of the same doses of angiotensin II on prandal drinking in food deprived animals. Under these conditions angiotensin II increased water consumption. Results were discussed in terms of the differential effects of angiotensin II on drinking, eating, and schedule dependent lever pressing.

Angiotensin II↗