Characterization of the electrophysiological and morphological properties of rat central amygdala neurons in vitro.
Forty central amygdala neurons labelled with 2% Neurobiotin were categorized according to their distinctive bioelectrical membrane properties and classified physiologically by their hyperpolarized resting membrane potential (-74 mV), short duration medium afterhyperpolarization (239.2 ms), and non-accommodating response as Type A neurons (63%; N = 25/40), or as Type B neurons (37%; N = 15/40) by their depolarized resting membrane potential (-66 mV), long slow-afterhyperpolarization (1.8 s), and accommodation response. Visualized within subnuclei of the central amygdala, Neurobiotin-labelled Type A neurons were medium-size cells [16.5 +/- 3 x 10.7 +/- 2 mu m; length x width] with smooth, spine-free ovoid, pyramiform, and fusiform perikarya. Aspinous primary dendrites gave rise to distal dendrites covered with numerous small pedunculated spines; density of spines ranged from sparse to abundant. Type B central amygdala neurons were larger cells [23.9 +/- 5 x 14.9 +/- 4 mu m] with smooth, aspinous ovoid, polygonal, and pyramiform somata. Dendrites were aspinous and covered with variably sized varicosities. Two distinct populations of neurons exist within the central amygdaloid complex: the medium-size, spine-laden Type A defined neuron with its non-accommodating electrophysiological response and the larger aspinous, varicosity-laden Type B defined neuron with its accommodating response. In contrast to their neighboring "cortical-like" amygdala neurons, central amygdala neurons possess a "striatal-like" cytoarchitecture and electrophysiology.
Schiess
M C
MC
Department of Neurology, University of Texas-Houston Medical School, Houston, USA. mschiess@neuro.med.uth.tmc.edu
Callahan
P M
PM
Zheng
H
H
D000200:Action Potentials / Q000502:physiology; D000679:Amygdala / Q000166:cytology / Q000502:physiology*; D000818:Animals; D048429:Cell Size; D004594:Electrophysiology; D008297:Male; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley