Characterization of the electrophysiological and morphological properties of rat central amygdala neurons in vitro

✍ Scribed by Mya C. Schiess; Patrick M. Callahan; Hua Zheng

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 376 KB
• Volume: 58
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19991201)58:5<663::aid-jnr7>3.0.co;2-a

✦ Synopsis

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 nonaccommodating 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 ؋ 10.7 ؎ 2 m; length ؋ 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 ؋ 14.9 ؎ 4 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, spineladen 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.