Multi-wire electrode arrays were used to record extracellular electrophysiological activity in striatal medium spiny-like neurons of freely-moving young (6-8 months) and aged (24-26 months) Fischer 344 rats. While overall basal firing rates did not differ between the two groups, d-amphetamine (5.0 mg/kg) increased firing rates more in the young rats. D-Amphetamine had heterogeneous effects on firing rates, however, exciting 63% of the neurons while inhibiting 37%. Neurons were classified according to their response to d-amphetamine (excited vs. inhibited) to examine age-related differences in firing rates and bursting activity. In the d-amphetamine-excited neurons, pre-drug intraburst firing rates were higher in the old rats. This effect was reversed by d-amphetamine. D-Amphetamine increased the percentage of spikes within bursts to a greater extent in the aged animals and decreased burst durations greater in the young group. In d-amphetamine-inhibited neurons, firing rates were diminished in the old rats more than they were in the young rats. These results demonstrate age-related alterations in striatal electrophysiological activity that may help explain motor deficits seen in senescence.
|Number of pages||11|
|Journal||Neurobiology of Aging|
|State||Published - 2001|
Bibliographical noteFunding Information:
This work was supported by grants from USPHS AG06434, AG13494-04, MH58414, and a level II Research Scientist Award (MH01245) to G. Gerhardt.
- Basal ganglia
ASJC Scopus subject areas
- Neuroscience (all)
- Clinical Neurology
- Developmental Biology
- Geriatrics and Gerontology