Multi-modal functional studies in rat somatosensory cortex: Heterogeneity across layers
Sanganahalli B, Herman P, Hyder F
The functional response to sensory stimuli is heterogeneous. We investigated the heterogeneity across the cortical layers for a given forepaw stimulus in the &[alpha]-chloralose anesthetized rat. The neurometabolic-neurovascular responses (BOLD, CBF, pO2) and electrical activity (AP, LFP) were measured in rat somatosensory cortex during 30 s forepaw stimulation (3 Hz, 2 mA, 0.3 ms) as a function of cortical depth. The contralateral responses were significantly larger than ipsilateral responses, both in size and amplitude for all modalities across all layers. The BOLD responses decreased across layers, from top to bottom, whereas the dynamics of the different signals were generally correlated.