Long-term potentiation in the neonatal rat barrel cortex in vivo.
Long-term potentiation (LTP) is important for the activity-dependent formation of early cortical circuits. In the neonatal rodent barrel cortex, LTP has been studied only in vitro. We combined voltage-sensitive dye imaging with extracellular multielectrode recordings to study whisker stimulation-induced LTP in the whisker-to-barrel cortex pathway of the neonatal rat barrel cortex in vivo. Single whisker stimulation at 2 Hz for 10 min induced an age-dependent expression of LTP in postnatal day (P) 0 to P14 rats, with the strongest expression of LTP at P3-P5. The magnitude of LTP was largest in the activated barrel-related column, smaller in the surrounding septal region, and no LTP could be observed in the neighboring barrel. Current source density analyses revealed an LTP-associated increase of synaptic current sinks in layer IV/lower layer II/III at P3-P5 and in the cortical plate/upper layer V at P0-P1. Our study demonstrates for the first time an age-dependent and spatially confined LTP in the barrel cortex of the newborn rat in vivo.
Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg University, D-55128 Mainz, Germany.
Shuming
S
An
Jenq-Wei
JW
Yang
Haiyan
H
Sun
Werner
W
Kilb
Heiko J
HJ
Luhmann
D000344:Afferent Pathways / Q000502:physiology; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001703:Biophysics; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D050486:Serotonin Plasma Membrane Transport Proteins / Q000378:metabolism; D013003:Somatosensory Cortex / Q000166:cytology* / Q000502:physiology; D018709:Statistics, Nonparametric; D014738:Vibrissae / Q000294:innervation; D056969:Voltage-Sensitive Dye Imaging / Q000379:methods
D050486:Serotonin Plasma Membrane Transport Proteins