Purkinje cell evoked unit activity in developing normal and undernourished rats.
Purkinje cell evoked unit activity was studied in developing normal and undernourished postnatal rats from 5 to 30 days. Ipsilateral electrical stimulation of the sciatic nerve, induced mossy fiber (MF) mediated simple spike activity or climbing fiber (CF) mediated complex multiple discharge activity. MF mediated response exhibited the phenomenon of electrical fatigue, while CF mediated response was augmented on repeated peripheral stimulation. Undernourished rats exhibited irregular and reduced spike amplitudes, spike frequencies, significantly increased stimulus thresholds and increased biological variabilities in their response on repeated electrical stimulation as compared to normal animals which exhibited a typical graded response at increasing stimulus frequencies and stimulus intensities. The after-hyperpolarization duration was also significantly increased in the undernourished as compared to normal rats. These data suggests that undernutrition, imposed during the lactation period can induce impairments in the Purkinje cell membrane dynamics and delays MF as well as CF mediated functional maturation in the developing cerebellum, which may induce delayed motor learning in young undernourished individuals.
Sharma
S K
SK
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.
Nayar
U
U
Maheshwari
M C
MC
Singh
B
B
D000818:Animals; D001835:Body Weight / Q000502:physiology; D002525:Cerebellar Cortex / Q000166:cytology / Q000254:growth & development / Q000502:physiology; D002531:Cerebellum / Q000166:cytology / Q000254:growth & development; D004558:Electric Stimulation; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology; D009412:Nerve Fibers / Q000502:physiology; D009748:Nutrition Disorders / Q000503:physiopathology*; D011689:Purkinje Cells / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000166:cytology / Q000502:physiology