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Biomedical subjects

R Bandler

Publications and source records attributed to R Bandler.

At least 73 records · Page 4Linked to original sources
PubMed1988

Elicitation of intraspecific defence reactions in the rat from midbrain periaqueductal grey by microinjection of kainic acid, without neurotoxic effects.

Microinjection of 40 pmol of the neuroexcitotoxin, kainic acid (KA) in the midbrain periaqueductal grey region (PAG) evoked a significant increase in both defensive and immobile behaviours in rats tested in a social situation. The evoked reactions appeared identical to the rat's natural defensive reaction to attack by a conspecific, although they were evoked by the presence, rather than the attack, of another rat. The long duration and natural appearance of the KA-evoked reactions stand in contrast to the short, 'explosive' reactions evoked by injection in the PAG of other excitant amino acids. There was no behavioural evidence of a diminution in the effect of repeated injections of KA in the PAG, nor was there any histological evidence of neurotoxicity.

Animals↗
PubMed1988

Integrated defence reaction elicited by excitatory amino acid microinjection in the midbrain periaqueductal grey region of the unrestrained cat.

Unilateral microinjections (0.20 microliter) of the excitatory amino acids (EAA), L-aspartate (ASP), D,L-homocysteate (DLH) or kainate (KA) were made into the midbrain of freely moving cats. Injections of DLH (20 nmol) or ASP (200 nmol) made within the midbrain periaqueductal grey matter (PAG) consistently elicited a threat display characteristic of defensive behaviour (i.e., pupillary dilatation, piloerection, retraction of the ears, sideways backing, arching of the back, hissing, howling, growling), whereas injections of DLH or ASP made in the tegmentum bordering the PAG did not elicit such behaviour. Injections of KA (940 pmol) made within the PAG, but not the tegmentum, elicited not only a threat display but also directed attack (striking with unsheathed claws and biting). As injections of EAA depolarize cell bodies, but not axons, the results suggest that a population of neurones whose excitation elicits all of the behavioural signs of defence, including directed attack, is found within the PAG. Histology indicated that the region of the PAG from which the defence reaction was elicited was not confined to any PAG subnucleus. Rather, the 'defence region' of the PAG formed a cylindrical column lateral to the midbrain aqueduct, approximately 1.5 mm in diameter and 5.0 mm in length, the rostral end of which lay dorsal to the caudal end. Further, it was found that EAA microinjections made in different portions of the defence region of the PAG elicited defence reactions characterised by different patterns of vocalization and differing intensities of display. It was also observed following unilateral injection of KA into the PAG that defence reactions, including attack, were elicited by approach in the visual hemifield or touch of the body contralateral, but not ipsilateral, to the injection site. The asymmetry of the defence reaction was not due to any obvious ipsilateral motor impairment and thus suggests that the PAG mediation of the defence reaction, in addition to controlling the outflow to the somatic and autonomic motor systems, also affects sensory processing.

Animals↗
PubMed1987

Excitation of neurones in a restricted portion of the midbrain periaqueductal grey elicits both behavioural and cardiovascular components of the defence reaction in the unanaesthetised decerebrate cat.

Microinjections of the excitant amino acid D,L-homocysteic acid (DLH) into a restricted part of the midbrain periaqueductal grey (PAG) of unanaesthetized decerebrate cats evoked a distinctive pattern of facio-vocal and cardiovascular changes characteristic of a defence reaction, including pupillary dilatation, howling vocalization, an increase in arterial pressure and heart rate, and skeletal muscle vasoconstriction. These facio-vocal and cardiovascular responses always occurred together, and thus may arise from excitation of a common population of neurones. DLH injections within a greater extent of the PAG elicited other facio-vocal changes characteristic of defence, such as hissing or growling, but these were not accompanied by significant cardiovascular changes.

Animals↗
PubMed1987

Midbrain periaqueductal grey region in the cat has afferent and efferent connections with solitary tract nuclei.

Wheat germ agglutinin-horseradish peroxidase (WGA-HRP) injections were made at the same sites within the midbrain periaqueductal grey region (PAG) of the cat at which microinjections of excitatory amino acids had previously elicited the set of autonomic and somatic reactions (i.e. pupil dilatation, piloerection, retraction of the ears, arching of the back, hissing, howling and growling) known as the 'defence reaction'. The WGA-HRP injections revealed that this PAG region has an extensive set of afferent and efferent connections with solitary tract nuclei (NTS). Within the NTS the majority of labelled neurons were distributed, in approximately equal numbers, in the ipsilateral medial solitary nucleus (SM) and the ipsilateral and the contralateral ventrolateral solitary nuclei (SVL). The densest anterograde labelling was found in the ipsilateral SM, with lighter anterograde labelling in the contralateral SM and bilaterally in the commissural solitary nucleus and SVL. The described connections between the defence region of the PAG and the NTS not only provide a new anatomical basis for cardiovascular and respiratory components of the reaction, but also add to the evidence that, in addition to the hypothalamus, the PAG is an important integrating center for the autonomic and somatic elements of the defence reaction.

Animals↗
PubMed1987

Ictal and enduring interictal disturbances in emotional behaviour in an animal model of temporal lobe epilepsy.

Unilateral microinjections of kainic acid (4.7 nmol) were made into the dorsal hippocampus of 17 unanesthetized freely moving cats. These injections provoked an acute period of intense seizure activity (first 48-72 h) which in 10 cats was followed by a chronic period of recurrent spontaneous complex partial seizures persisting for as long as the cats were studied (up to 4 months). During the chronic epileptic period 8 of these 10 cats demonstrated both ictal and interictal emotional behaviour disturbances. The ictal events included behaviour similar to a 'defensive rage' reaction. Interictally, each of the cats demonstrated an emotional lability. That is, although they behaved in a normal manner if handled affectionately, any mild provocation triggered an explosive defensive rage reaction. As well, the thresholds for electrical brain stimulation induced defensive rage were lowered. That the interictal emotional behaviour disturbances were related to the presence of an active epileptogenic process was suggested by the finding that during periods when no spontaneous seizures were observed for several days, the cats reverted to a less emotionally reactive state and the thresholds for stimulation-induced defence reactions returned to baseline. The results indicate that epileptogenic lesions of the temporal lobe alone can induce an enduring disturbance of emotional behaviour. They support the view that emotional disturbances in patients with epilepsy may sometimes result from pathophysiological mechanisms related to the epileptogenic process, and further suggest that such emotional disturbances might be reversed or prevented if the epileptic seizures could be controlled.

Animals↗
PubMed1986

Neurobiology of behavior: anatomic and physiological implications related to epilepsy.

Controversy exists concerning whether epileptic seizures can produce enduring alterations in neuronal function that cause interictal behavioral disturbances. Although arguments favoring the occurrence of epilepsy-induced disorders of behavior must not be presented in a way that adds to the stigmata associated with epilepsy, it is not in the best interest of epileptic patients to deny this possible relationship and overlook an opportunity to prevent or treat a major cause of disability. There is evidence to suggest that psychosocial factors cannot account for all the behavioral problems suffered by patients with epilepsy. Behavioral disturbances ascribed to antiepileptic drugs and specific structural lesions may also be due, in part, to epileptogenic mechanisms. Some interictal behavioral disturbances may actually reflect unrecognized ictal events. Most importantly, data obtained from clinical research and animal investigations suggest testable hypotheses of how recurrent epileptic seizures can alter neuronal function in ways that would predispose to specific disruptive interictal behaviors, such as aggression, depression and schizophrenia.

Aggression↗
PubMed1986

Fluorescence microscopy procedure for quantitation of yeasts in beverages.

Existing methods for quantitating yeasts in beverages include time-consuming plate counts that detect only living cells and hemacytometer counts that are reliable only at very high concentrations (e.g., 10(6) to 20 X 10(6) cells per ml). The new method described here involves the use of fluorescence microscopy with the fluorescent stain aniline blue to differentiate yeasts (and other fungi) from backgrounds for easy counting and also may be used in conjunction with membrane filtration to concentrate yeasts from liquids before cell enumeration. Recoveries averaged 91.5% for beverages spiked with levels of 500 to 600,000 organisms per ml. The correlation coefficient of count to spike level was 0.996.

Beverages↗
PubMed1985

Cardiovascular components of the defence reaction evoked by excitation of neuronal cell bodies in the midbrain periaqueductal grey of the cat.

In the anaesthetized and paralyzed cat the cardiovascular pattern characteristic of the defence reaction, i.e. skeletal muscle vasodilatation, tachycardia and increased arterial pressure, was elicited by microinjections (0.40 microliter) of the excitatory amino acid, DL-homocysteic acid (DLH), into the midbrain periaqueductal grey (PAG) matter. In contrast, injections of DLH into the midbrain tegmentum failed to elicit the cardiovascular components of the defence reaction. As injections of DLH depolarize cell bodies but not axons, the results indicate that the midbrain PAG, but not the adjacent tegmentum, contains a population of neurones whose excitation elicits these reactions. Further, the data suggested that such neurones may be localized preferentially within the caudal half of the midbrain PAG.

Animals↗
PubMed1985

Further localization of midbrain neurones mediating the defence reaction in the cat by microinjections of excitatory amino acids.

Microinjections (0.05 microliter) of L-glutamic acid, L-aspartic acid and DL-homocysteic acid were made in the midbrain at the same sites from which a defence reaction had been elicited previously by electrical stimulation. It was found that injections made at sites within the midbrain periaqueductal grey region (PAG) consistently elicited the facio-vocal signs of the defence reaction, whereas injections made at sites in the tegmentum bordering the PAG did not. As injections of excitatory amino acids depolarize cell bodies but not axons, the results indicate that the midbrain PAG but not the adjacent tegmentum contains a population of neurones whose excitation elicits these reactions. Furthermore, the data suggested that such neurones may be located preferentially within the caudal half of the midbrain PAG.

Amino Acids↗
PubMed1985

Afferents to a midbrain periaqueductal grey region involved in the 'defence reaction' in the cat as revealed by horseradish peroxidase. I. The telencephalon.

Horseradish peroxidase injections were made at sites, within the midcollicular portion of the midbrain periaqueductal grey region (PAG), at which both electrical stimulation and subsequent microinjections of excitatory amino acids elicited defensive behaviour. Since excitatory amino acids depolarize cell bodies and dendrites located in the vicinity of the injection site but not axons of passage, the injections were centred within a PAG region known to contain neurones whose excitation elicited defensive behaviour. The telencephalic afferents to these sites were then determined. Sixty percent of the labelled telencephalic neurones were found in the frontal cortex, specifically in the medial frontal cortex along the banks of the rostral two-thirds of the cruciate sulcus, primarily area 6 and area 4, and the medial frontal cortex ventral to area 6 (area 32). Twenty-five percent of the labelled telencephalic neurones were found in the orbito-insular cortex while 8% were found in the parietal cortex surrounding the anterior ectosylvian sulcus. Although the functional significance of these projections remains to be established, available data suggest that these projections to the PAG arise from frontal 'oculomotor' and motor cortices, a polysensory insular cortical region and somatosensory, visual and auditory parietal cortical areas.

Aggression↗
PubMed1985

Identification of midbrain neurones mediating defensive behaviour in the rat by microinjections of excitatory amino acids.

Unilateral microinjections (0.20 microliter) of excitatory amino acids were made into the midbrain of freely moving rats. Injections made within the midbrain periaqueductal grey matter (PAG) consistently elicited reactions characteristic of defensive behaviour (i.e. explosive jumps, freezing, upright postures), whereas injections made in the tegmentum bordering the PAG did not as reliably elicit such behaviour. As injections of excitatory amino acids depolarize cell bodies but not axons, the results suggest that a population of neurones whose excitation elicits these reactions is found primarily within the midbrain PAG of the rat. Furthermore, the data suggested that such neurones may be localized preferentially within the caudal half of the midbrain PAG. Injections of the GABA antagonist, bicuculline methiodide, at many of the same midbrain sites produced behaviour similar to that elicited by excitatory amino acids indicating a possible GABAergic modulation of these same PAG-mediated reactions. It also was observed following unilateral injection into the PAG, of either the excitatory amino acid, L-aspartic acid or bicuculline, that defensive behaviour was elicited by touching the rat on the body or snout contralateral but not ipsilateral to the injection site. This suggests that the induction of defensive behaviour by unilateral PAG stimulation is due, at least in part, to lateralized alterations in sensorimotor responsiveness.

Amino Acids↗
PubMed1984

Afferents to a midbrain periaqueductal grey region involved in the 'defense reaction' in the cat as revealed by horseradish peroxidase. II. The diencephalon.

Horseradish peroxidase injections were made at the same sites, within the midcollicular portion of the midbrain periaqueductal grey region (PAG), at which electrical stimulation and microinjections of excitatory amino acids elicited defensive behaviour. The diencephalic afferents to these sites were then studied. Seventy eight percent of the labelled diencephalic neurons were found within the tuberal portion of the hypothalamus, specifically in 3 regions: (a) the ventromedial hypothalamic nucleus and adjacent perifornical area; (b) the region of the tuber cinereum, ventral and medial to the ventromedial hypothalamic nucleus; (c) the region of paraventricular and parvocellular hypothalamic nuclei. A control injection of HRP at a site, in the tegmentum immediately adjacent to the PAG, at which electrical stimulation elicited defensive behaviour, but excitatory amino acid injections did not, suggested that the extensive labelling of neurones within the tuberal region of the hypothalamus was specific to the HRP injections being made at PAG sites at which excitatory amino acid injections elicited defensive behaviour.

Aggression↗
PubMed1982

Lateralized loss of biting attack-patterned reflexes following induction of contralateral sensory neglect in the cat: a possible role for the striatum in centrally elicited aggressive behaviour.

A syndrome of "contralateral sensory neglect' was induced by hypothalamic knife cuts in 6 of 10 cats in which quiet biting attack behaviour could be elicited by lateral hypothalamic stimulation. The contralateral sensory neglect in the 6 affected cats was accompanied by a loss on the "neglected' side of the body of the patterned reflexes which mediate positioning of the head to bite and the jaw-opening component of biting. As a result, when these cats were stimulated in the lateral hypothalamus, although they continued to approach and even make tactile contact with the rat, they generally failed to bite it. Analysis of the histological and behavioural data suggested that damage to the nigrostriatal and/or striato/pallidonigral fibre systems provided the likely basis for both the induction of the contralateral sensory neglect and the lateralized patterned reflex loss. It was suggested, with respect to these specific patterned reflex components of the attack, that an important contribution may be made by the striatum.

Animals↗
PubMed1982

Induction of 'rage' following microinjections of glutamate into midbrain but not hypothalamus of cats.

Microinjections of glutamic acid were made into the same midbrain and hypothalamic sites of cats at which 'defensive-rage' behaviour was elicited by electrical stimulation. It was found that : (1) medial hypothalamic and midbrain tegmental glutamate injections were without behavioural effect; (2) midbrain periaqueductal grey injections elicited a 'rage' display. Since glutamate depolarizes cell bodies but not axons, the results suggest that there is a specific population of neurones in the midbrain whose excitation elicits this reaction.

Anger↗
PubMed1982

A method for evoking physiological responses by stimulation of cell bodies, but not axons of passage, within localized regions of the central nervous system.

A method for evoking physiological responses by microinjection of sodium glutamate solution into localized regions of the central nervous system (CNS) is described. The major advantage of this method is that the cell bodies or dendritic processes of neurones within the injection site are excited, whereas axons of passage are unaffected. It was demonstrated that injections of minute volumes (50-100 nl) of 0.5 M glutamate solution into selected sites within the medulla or midbrain of anaesthetized or conscious animals, respectively, elicited marked autonomic, somatomotor or behavioural responses, depending on the injection site. In contrast, glutamate microinjection into fibre tracts failed to elicit any response, whereas electrical stimulation applied at the same sites elicited marked responses. The degree of localization of the glutamate stimulus and the relation between glutamate concentration and magnitude of evoked response are described. It is concluded that this method is a very effective means of selectively stimulating cell bodies within highly localized regions of the CNS. Further, by using this method in combination with focal electrical stimulation, it is possible in some cases to provide evidence that a response arises from excitation of axons of passage rather than cell bodies.

Animals↗
PubMed1982

Determination of Geotrichum mold in comminuted fruits and vegetables: collaborative study.

The official AOAC method for determination of Geotrichum mold in canned fruits and vegetables (44.079) requires a series of 3 sieves, Nos. 8, 16, and 230, to separate the packing liquid from the product and the mold from the packing liquid. Although this method has been successful for whole or coarsely chopped products (e.g., green beans, potatoes, carrots, and beets), finely divided products such as fruit purees and tomato products tend to clog the sieves. A method was developed in which the product is centrifuged, diluted by volume, stained with crystal violet, and counted with the sieving steps eliminated. The proposed method was adopted official first action.

Food Microbiology↗
PubMed1982

Howard mold count of fruit nectars, purees, and pastes: collaborative study.

The various mold count methods for nectars, purees, and pastes make no adjustment for concentration of the pulped liquid. Thus, mold counts of different forms of the same product (e.g., guava nectar, puree, or paste) or of the same product from different manufacturers cannot be compared. A method was developed in which the product is centrifuged under standardized conditions, then diluted to a standard pellet-to-final-volume ratio. Because variations in the concentration of fruit or vegetable tissue are corrected, comparisons of mold counts are possible. The method was adopted official first action.

Centrifugation↗