Centripetal and centrifugal reorganizations of frequency map of auditory cortex in gerbils

AUTOR(ES)

Sakai, Masashi

FONTE

The National Academy of Sciences

RESUMO

As repetitive acoustic stimulation and auditory conditioning do, electric stimulation of the primary auditory cortex (AI) evokes reorganization of the frequency map of AI, as well as of the subcortical auditory nuclei. The reorganization is caused by shifts in best frequencies (BFs) of neurons either toward (centripetal) or away from (centrifugal) the BF of stimulated cortical neurons. In AI of the Mongolian gerbil, we found that focal electrical stimulation evoked a centripetal BF shift in an elliptical area centered at the stimulated neurons and a centrifugal BF shift in a zone surrounding it. The 1.9-mm long major and 1.1-mm long minor axes of the elliptical area were parallel and orthogonal to the frequency axis, respectively. The width of the surrounding zone was 0.2–0.3 mm. Such “center-surround” reorganization has not yet been found in any sensory cortex except AI of the gerbil. The ellipse is similar to the arborization pattern of pyramidal neurons, the major source of excitatory horizontal connections in AI, whereas the surrounding zone is compatible to the arborization range of small basket cells (inhibitory neurons) in AI.

Documentos Relacionados

• Memory Consolidation for the Discrimination of Frequency-Modulated Tones in Mongolian Gerbils Is Sensitive to Protein-Synthesis Inhibitors Applied to the Auditory Cortex
• Plasticity of the cochleotopic (frequency) map in specialized and nonspecialized auditory cortices
• Experience-dependent corticofugal adjustment of midbrain frequency map in bat auditory system
• Histamine and thrombin modulate endothelial focal adhesion through centripetal and centrifugal forces.
• GABA Shapes Selectivity for the Rate and Direction of Frequency-Modulated Sweeps in the Auditory Cortex