Amygdala central nucleus lesions: Effect on heart rate conditioning in the rabbit

Abstract The present study was designed as an initial step in determining the specific anatomical systems of the amygdala which may contribute to the expression of conditioned heart rate responding during aversive Pavlovian conditioning in the New Zealand rabbit. Animals receiving either small or large radio-frequency lesions of the central nucleus of the amygdala demonstrated a significant attenuation of the conditioned bradycardia response to the conditioned stimulus when compared to that demonstrated by control animals. No significant effects of the lesions on baseline heart rate or on the heart rate orienting response to the conditioned stimulus were observed. Central nucleus lesions also produced a significant effect on the unconditioned heart rate response to the unconditioned stimulus manifested in an increased duration and prolonged habituation of the unconditioned response. The results are consistent with anatomical and physiological evidence suggesting the involvement of the central nucleus in the expression of emotional responses including accompanying cardiovascular alterations.

[1]  N. Schneiderman,et al.  Aortic nerve-activated cardioinhibitory neurons and interneurons. , 1975, The American journal of physiology.

[2]  B. Slotnick.  Fear behavior and passive avoidance deficits in mice with amygdala lesions. , 1973, Physiology & behavior.

[3]  V. C. Abrahams,et al.  Active muscle vasodilatation produced by stimulation of the brain stem: its significance in the defence reaction , 1960, The Journal of physiology.

[4]  J. Coote,et al.  The pontomedullary area integrating the defence reaction in the cat and its influence on muscle blood flow , 1973 .

[5]  G. V. Goddard.  FUNCTIONS OF THE AMYGDALA. , 1964, Psychological bulletin.

[6]  W. L. Milligan,et al.  Autonomic-somatic relationships: blockade of heart rate and corneo-retinal potential responses. , 1973, Journal of comparative and physiological psychology.

[7]  M. H. Evans.  Stimulation of the rabbit hypothalamus: caudal projections to respiratory and cardiovascular centres. , 1976, The Journal of physiology.

[8]  I. Gormezano,et al.  Heart rate classical conditioning in rabbits , 1966 .

[9]  G. Mogenson,et al.  Cardiovascular responses to electrical stimulation of the amygdala in the rat. , 1973, Experimental neurology.

[10]  M. H. Evans.  Potentiation of a cardioinhibitory reflex by hypothalamic stimulation in the rabbit , 1978, Brain Research.

[11]  R. Dafters.  Effect of medial archistriatal lesions on the conditioned emotional response and on auditory discrimination performance of the pigeon , 1976, Physiology & Behavior.

[12]  A. Spevack,et al.  Effect of amygdalectomy on habituation and CER in rats , 1975, Physiology & Behavior.

[13]  L. Pellegrino.  Amygdaloid lesions and behavioral inhibition in the rat. , 1968, Journal of comparative and physiological psychology.

[14]  D. Reis,et al.  BRADYCARDIA AND TACHYCARDIA FOLLOWING ELECTRICAL STIMULATION OF THE AMYGDALOID REGION IN MONKEY. , 1964, Journal of neurophysiology.

[15]  D. H. Vandercar,et al.  Nictitating membrane and corneo-retinal transducers for conditioning in rabbits. , 1969, The American psychologist.

[16]  B. Anand,et al.  Circulatory and respiratory changes induced by electrical stimulation of limbic system (visceral brain). , 1956, Journal of neurophysiology.

[17]  A. Zbrożyna,et al.  Amygdaloid region for defence reactions and its efferent pathway to the brain stem , 1963, The Journal of physiology.

[18]  M. Kellicutt,et al.  Formation of a Conditioned Emotional Response (CER) Following Lesions of the Amygdaloid Complex in Rats , 1963 .

[19]  F. Horvath.  Effects of basolateral amygdalectomy on three types of avoidance behavior in cats. , 1963, Journal of comparative and physiological psychology.

[20]  H. Ursin.  EFFECT OF AMYGDALOID LESIONS ON AVOIDANCE BEHAVIOR AND VISUAL DISCRIMINATION IN CATS. , 1965, Experimental neurology.

[21]  N. Schneiderman,et al.  Selective autonomic blockade of conditioned and unconditioned heart rate changes in rabbits. , 1974, Pharmacology, biochemistry, and behavior.

[22]  A. Zbrożyna.  The Organization of the Defence Reaction Elicited from Amygdala and Its Connections , 1972 .

[23]  G. Mogenson,et al.  Pathway mediating hypotension elicited by stimulation of the amygdala in the rat. , 1975, The American journal of physiology.

[24]  D. Blanchard,et al.  Innate and conditioned reactions to threat in rats with amygdaloid lesions. , 1972, Journal of comparative and physiological psychology.

[25]  N. Schneiderman,et al.  Vagal compensatory adjustment: relationship to heart rate classical conditioning in rabbits. , 1969, Journal of comparative and physiological psychology.

[26]  T. L. Holdstock.  Autonomic reactivity following septal and amygdaloid lesions in white rats , 1969 .

[27]  H. Ursin,et al.  Corticosterone and avoidance in rats with basolateral amygdala lesions. , 1973, Journal of comparative and physiological psychology.

[28]  B. Kapp,et al.  Passive avoidance and amygdala lesions: Relationship with pituitary-adrenal system , 1976, Physiology & Behavior.

[29]  L. Weiskrantz,et al.  Behavioral changes associated with ablation of the amygdaloid complex in monkeys. , 1956, Journal of comparative and physiological psychology.

[30]  M H Bagshaw,et al.  Multiple measures of the orienting reaction and their dissociation after amygdalectomy in monkeys. , 1968, Experimental neurology.

[31]  H. Ursin,et al.  Functional localization within the amygdaloid complex in the cat. , 1960, Electroencephalography and clinical neurophysiology.

[32]  J. Price,et al.  A description of the amygdaloid complex in the rat and cat with observations on intra‐amygdaloid axonal connections , 1978, The Journal of comparative neurology.

[33]  R. Hunsperger,et al.  Organization of the subcortical system governing defence and flight reactions in the cat , 1962, The Journal of physiology.

[34]  I. Urban,et al.  A stereotaxic atlas of the New Zealand rabbit's brain , 1972 .

[35]  D. Cohen.  Involvement of the avian amygdalar homologue (archistriatum posterior and mediale) in defensively conditioned heart rate change , 1975, The Journal of comparative neurology.

[36]  J. Ashe,et al.  Effects of basolateral amygdala lesions on neophobia, learned taste aversions, and sodium appetite in rats. , 1974, Journal of comparative and physiological psychology.

[37]  N. Schneiderman,et al.  Correlates of heart-rate classical conditioning in curarized rabbits. , 1967, Journal of comparative and physiological psychology.

[38]  A. Fernández de Molina,et al.  Electrographic study of the amygdaloid defense response. , 1974, Physiology & behavior.