Single neuron responses in amygdala of alert monkey during complex sensory stimulation with affective significance

Abstract

Among other deficits, amygdalectomy impairs the ability of the animal to recognize the affective significance of a stimulus. In the present study, neuronal activity in the amygdala (AM) was recorded from alert monkeys while they performed tasks leading to the presentation of rewarding or aversive stimuli. Of 585 AM neurons tested, 312 (53.3%) responded to at least one stimulus in one or more of 5 major groups: 40 vision related, 26 audition related, 41 ingestion related, 117 multimodal, and 14 selective. Ingestion-related neurons were subdivided according to their responses to other stimuli: oral sensory, oral sensory plus vision, and oral sensory plus audition. Depending upon their responsiveness to the affective significance of the stimuli, neurons in the vision- and audition-related categories were divided into 2 subclasses: vis-I (26/40), vis-II (14/40), aud-I (8/26), and aud-II (18/26). All 4 subtypes usually responded to unfamiliar stimuli but seldom responded to neutral familiar stimuli. Types vis-I and aud-I responded to both positive and negative familiar stimuli. Types vis-II and aud-II responded to certain familiar negative stimuli but not to familiar positive stimuli. In vis-I neurons, responses were stronger for palatable foods than for less palatable foods. No neurons within vision-related, audition-related, and multimodal categories responded solely to positive or to negative stimuli. Of the 27 oral sensory neurons 9 were tested with saline or salted food, and 8 responded to normally aversive oral sensory stimuli in the same manner as they did to normal food or liquid (water or juice). In contrast to oral sensory neurons, all responses of 4 oral sensory-plus-vision and all of 4 selective neurons tested, as well as bar pressing behavior, were modulated by altering the affective significance of the food. These results suggest that the AM is one of the candidates for stimulus-affective association based on associative learning and memory.

Systemic administration of the benzodiazepine receptor partial inverse agonist FG‐7142 disrupts corticolimbic network interactions

“…Given that NMDA receptor hypofunction and FG-7142 treatment have similar effects on mPFC bursting and working memory (Birnbaum et al, 1999;Murphy et al, 1996), burst firing in mPFC may play a critical role in mediating cognitive functions such as attention and vigilance (Krahe and Gabbiani, 2004). Similarly, amygdaloid bursts occur in response to affectively relevant stimuli (Nishijo et al, 1988). Moreover, bursting in individual BLA neurons may facilitate synaptic transmission in neighboring cells and thus promote burst firing in populations of excitatory projection neurons (Paré et al, 1995).…”

Dopaminergic and non-dopaminergic value systems in conditioning and outcome-specific revaluation

“…Many neurons have characteristic activation profiles that allow them to be classified as exemplars of a functional cell type (Ono et al, 1986b;Nishijo et al, 1988a;Tremblay and Schultz, 2000b). The activation profiles of eleven neural cell types were simulated by model neurons.…”

“…US value cells are located in the amygdala (AMYG) and help explain observations of neurons in the amygdala that selectively respond to specific foods or associated stimuli in a manner that reflects the expected consumption value of the food (e.g. Nishijo et al, 1988aNishijo et al, , 1988b. Fig.…”

“…In particular, experiments that assay neuronal responses during trials where juice is consumed with increasing satiety have found that neurons have a logistically decreasing response to US or CS presentation as satiety increases (Rolls et al, 1986;Critchley and Rolls, 1996). The model exhibits the FSS property in that both simulated and electrophysiologically recorded neurons in the AMYG, LH, ORB have diminished responses to a sated food, but preserved responses to an unsated food (Rolls et al, 1986;Nishijo et al, 1988a). At a behavioral level, animals show depressed Pavlovian responding to a CS that has been selectively devalued (Hatfield et al, 1996).…”

“…AMYG cell activities,ri A , model multimodal, US-selective cells found in the basolateral amygdala (Nishijo et al, 1988a(Nishijo et al, , 1988b …”