Faculty Collaboration Database

Maintenance of inhibitory interneurons and boutons in sensorimotor cortex between middle and old age in Fischer 344 X Brown Norway rats. J Chem Neuroanat 2006 Aug;32(1):46-53

Date

05/25/2006

Pubmed ID

16720092

DOI

10.1016/j.jchemneu.2006.04.001

Scopus ID

2-s2.0-33747167071 (requires institutional sign-in at Scopus site)   11 Citations

Abstract

Ultrastructurally identified inhibitory synapses in layer II of rat sensorimotor cortex decline between middle and old age [Poe, B.H., Linville, C., Brunso-Bechtold, J., 2001. Age-related decline of presumptive inhibitory synapses in the sensorimotor cortex as revealed by the physical disector. J. Comp. Neurol. 439, 65-72]. The current study investigated whether a loss or shrinkage of gamma-aminobutyric acid (GABA)ergic interneurons contribute to that decline. Coronal sections from middle-aged (15-17 months) and old (25-29 months) Fischer 344 X Brown Norway male rats were immunoreacted with antibodies to the GABA synthesizing enzyme glutamic acid decarboxylase (GAD); the calcium-binding protein parvalbumin (PV), or the neuronal marker NeuN. The number of GAD-immunoreactive (IR), PV-IR, and NeuN-IR cells were determined stereologically using the optical disector technique and the cross-sectional areas of GAD-IR cells were measured in layers II/III, IV, V and VI of sensorimotor cortex. Neither the number of GAD-IR or NeuN-IR cells, nor the size of GAD-IR cells, declined significantly between middle and old age. A modest decline in the PV-IR subset of inhibitory interneurons was observed, predominantly due to changes in layers V and VI. Stereological analysis of layer II/III GAD-IR boutons revealed a stability of immunocytochemically identified inhibitory terminals. Taken together, these results indicate a general maintenance of overall GABAergic neurons in sensorimotor cortex between middle and old age and the loss of ultrastructurally identified inhibitory synapses may be due to the decline of a subset of GABAergic terminals.

Author List

Shi L, Pang H, Linville MC, Bartley AN, Argenta AE, Brunso-Bechtold JK

MESH terms used to index this publication - Major topics in bold

Aging
Animals
Cerebral Cortex
Glutamate Decarboxylase
Image Processing, Computer-Assisted
Immunohistochemistry
Interneurons
Male
Nerve Tissue Proteins
Nuclear Proteins
Parvalbumins
Presynaptic Terminals
Rats
Rats, Inbred BN
Rats, Inbred F344
gamma-Aminobutyric Acid