Neurochemical Research

, Volume 32, Issue 2, pp 177–186 | Cite as

Co-localization of Glutamic Acid Decarboxylase and Phosphate-activated Glutaminase in Neurons of Lateral Reticular Nucleus in Feline Thalamus

  • Robin Scott Fisher


Immunohistochemical methods were used to label singly and/or in combination glutamic acid decarboxylase (GAD, the sole synthesizing enzyme for the inhibitory neurotransmitter γ-aminobutyric acid) and phosphate-activated glutaminase (GLN, a synthesizing enzyme for glutamate) in neurons of lateral reticular nucleus (LRN) of thalamus of adult cats. (1) GAD- and GLN-immunoreactivity (IR) exhibited matching regional patterns of organization within LRN. (2) GAD- and GLN-IR co-localized within most if not all LRN neuronal cell bodies as shown by light microscopy. (3) GAD- and GLN-IR had distinct subcellular localizations in LRN neurons as shown by correlative light/electron microscopy. LRN neurons are important conceptual models where strongly inhibitory cells receive predominant excitatory glutamatergic afferents (from neocortex). Consistent with known actions of intermediary astrocytes, LRN neurons demonstrate GLN enrichment synergistically coupled with glutamatergic innervation to supplement the glutamate pool for GABA synthesis (via GAD) and for metabolic utilization (via the GABA shunt/tricarboxylic acid cycle) but not, apparently, for excitatory neurotransmission.


GAD GABA Glutaminase Glutamate Co-localization Thalamus 



Primary antibodies employed in this investigation were received as gifts from the following investigators: Irwin Kopin (GAD), Norman Curthoys (GLN) and Peter Petrusz (glutamate). Janelle Asai provided technical services particularly for correlative light and electron microscopy. Supported by USPHS grants HD 05958, IT32MH1534, and RR 05756.


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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Psychiatry and NeurobiologyMental Retardation Research Center, UCLA Geffen School of MedicineLos AngelesUSA

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