[Interaction and firing pattern of rabbit amygdalar neurons in the state of unconditioned fear manifested as freezing].
In order to reveal characteristics of functioning of amygdalar neuronal network during unconditioned fear, firing patterns of basal and central nuclear neurons and their interaction were studied during freezing (fear), active unconditioned motor reactions (in the absence of fear) to emotionally significant stimuli, and during quiet wakefulness. As compared to other states, specific changes in interaction of adjacent amygdalar neurons took place during freezing. Such changes were not revealed in firing of single neurons. During freezing, the number of short-latency (to 100 ms) excitatory connections increased and the number of long-latency (250-450 ms) inhibitory connections decreased. In freezing, more frequently than in other states, delta-2 range frequencies (from 2 to 4 Hz) were observed in the interneuronal interaction. During active locomotor reactions to stimuli, the number of interacting neurons decreased, the number of long-latency (200-250 ms) excitatory and short-latency (50-200 ms) inhibitory connections decreased, and theta 1-range frequencies were frequently observed in the interaction. It was concluded that, for the development of fear, the balance between excitatory and inhibitory links of amygdalar neuronal network is essential.
Rysakova
M P
MP
Pavlova
I V
IV
D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D005239:Fear / Q000502:physiology*; D046352:Freezing Reaction, Cataleptic / Q000502:physiology*; D008297:Male; D009415:Nerve Net; D009434:Neural Pathways; D009474:Neurons / Q000502:physiology*; D011817:Rabbits