Enhanced short-latency responses in the ventral posterior medial (VPM) thalamic nucleus following whisker trimming in the adult rat.
This study examined the effects of whisker trimming on the functional organization of the adult somatosensory thalamus. In vivo extracellular unit recordings were made on ventral posterior medial (VPM) thalamic neurons in urethane anaesthetised adult rats. Neuronal response properties to controlled whisker deflection were recorded in untrimmed control animals and in animals where one row of whiskers had been trimmed for a median of 18 days. Trimming significantly increased short-latency responses to stimulation of the centre receptive field whisker (mean increase of 36%, p<.001). Longer latency responses to surround receptive field whiskers were unaffected. Spontaneous firing was significantly decreased in trimmed animals. A condition-test paradigm indicated that thalamic inhibition was reduced following whisker trimming, although this effect failed to reach statistical significance. These results demonstrate a capacity of the adult somatosensory thalamus to undergo functional reorganization in response to non-traumatic and innocuous whisker trimming.
Dolan
Sharron
S
Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, UK.
Cahusac
Peter M B
PM
D000200:Action Potentials / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001931:Brain Mapping; D008297:Male; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology*; D012683:Sensory Deprivation / Q000502:physiology*; D013997:Time Factors; D020651:Ventral Thalamic Nuclei / Q000166:cytology / Q000502:physiology*; D014738:Vibrissae / Q000294:innervation*