Characterization of strychnine-sensitive glycine receptors in acutely isolated adult rat basolateral amygdala neurons

• Published in: Brain research Vol. 859; no. 2; pp. 341 - 351
• Main Authors: McCool, Brian A, Botting, Shaleen K
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 24.03.2000; Amsterdam Elsevier; New York, NY
• Subjects: Amygdala - cytology; Amygdala - drug effects; Amygdala - metabolism; Animals; Basolateral amygdala; Biological and medical sciences; Cell Culture Techniques; Cell Membrane - drug effects; Cell Membrane - metabolism; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Chloride Channels - drug effects; Chloride Channels - metabolism; Electrophysiology; Fundamental and applied biological sciences. Psychology; gamma-Aminobutyric Acid - metabolism; Glycine - metabolism; Glycine receptor; Male; Neurons - cytology; Neurons - drug effects; Neurons - metabolism; Patch-Clamp Techniques; Rats; Receptors, GABA-A - drug effects; Receptors, GABA-A - metabolism; Receptors, Glycine - drug effects; Receptors, Glycine - metabolism; Strychnine; Strychnine - pharmacology; taurine; Taurine - metabolism; Taurine - pharmacology; Vertebrates: nervous system and sense organs; Basolateral amygdala; Electrophysiology; Strychnine; Glycine receptor; Characterization; Vertebrata; Mammalia; Amygdala; Rat; Rodentia; Central nervous system; Basal ganglion; Brain (vertebrata)
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(00)02026-6

Large concentrations of the β-amino acid, taurine, can be found in many forebrain areas such as the basolateral amygdala, a portion of the limbic forebrain intimately associated with the regulation of fear/anxiety-like behaviors. In addition to its cytoprotective and osmoregulatory roles, taurine may also serve as an agonist at GABA A- and strychnine-sensitive glycine receptors. In this latter context, the present study demonstrates that application of taurine to acutely isolated neurons from the basolateral amygdala of adult rats causes significant alterations in resting membrane current, as measured by whole-cell patch clamp electrophysiology. Using standard pharmacological approaches, we find that currents gated by concentrations of taurine ≤3 mM are predominantly mediated by strychnine-sensitive receptors. Furthermore, these strychnine-sensitive receptors are shown to be pharmacologically and biophysically similar to `classic' strychnine-sensitive, chloride-conducting glycine receptors expressed in brainstem and spinal cord. While amygdala glycine receptors can be distinguished from GABA A receptors expressed by the same neurons, these two chloride channels are functionally expressed at comparable levels. Given that a number of clinically relevant compounds are associated with the regulation of GABA A receptors in this brain region, the presence of both strychnine-sensitive glycine receptors and their agonist, taurine, in the basolateral amygdala may suggest an important role for these receptors in the limbic forebrain of adult rats.