Premium
Transient increase in expression of GAD 65 and GAD 67 mRNAs during postnatal development of rat spinal cord
Author(s) -
Ma Wu,
Behar Toby,
Chang Lisa,
Barker Jeffery L.
Publication year - 1994
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903460111
Subject(s) - biology , spinal cord , neuroscience , transient (computer programming) , operating system , computer science
Gamma‐aminobutyric acid (GABA) is thought to be one of the classic neurotransmitters acting as a developmental signal. To understand the role for GABA in development, we investigated the expression of transcripts encoding two forms of the GABA‐synthesizing enzyme glutamate decarboxylase (GAD 65 and GAD 67 ) in the cervical enlargement of the rat spinal cord at successive postnatal days—P0, P7, P14, P21, and P90 (adult)—by using in situ hybridization histochemistry. Cells hybridized with two oligonucleotide probes designed to detect GAD 65 and GAD 67 mRNAs were widely distributed in all laminae, except in motoneurons of the spinal cord. The integrated densities of hybridization signals were measured across all layers of the gray matter. The relative number of GAD mRNA‐labeled cells was determined within each of four regions: laminae I–;III, laminae IV–VI, laminae VII and VIII, and lamina X. There was a transient increase in both the integrated density and the relative number of hybridized cells between P7 and P14, after which there was a marked decline to adult levels (lowest). An overall decrease in the number of GAD mRNA‐labeled cells was evident in all layers, but a dramatic drop occurred in a subpopulation of cells within ventral portions of the spinal cord. The distribution patterns and postnatal changes in expression of the mRNAs encoding GAD 65 and GAD 67 were similar and closely paralleled reported changes in the abundance of GAD 65 and GAD 67 proteins and their product, GABA. Transient increases in GAD mRNA expression during the early postnatal period coincide with, and may be linked to, synapse formation and synapse elimination of the developing spinal cord. © 1994 Wiley‐Liss, Inc.