Physiological differences between histologically defined subdivisions in the mouse auditory thalamus

Hear Res. 2011 Apr;274(1-2):48-60. doi: 10.1016/j.heares.2010.12.016. Epub 2010 Dec 24.

Abstract

The auditory thalamic area includes the medial geniculate body (MGB) and the lateral part of the posterior thalamic nucleus (Pol). The MGB can be subdivided into a ventral subdivision, forming part of the lemniscal (primary) auditory pathway, and medial and dorsal subdivisions, traditionally considered (alongside the Pol) part of the non-lemniscal (secondary) pathway. However, physiological studies of the auditory thalamus have suggested that the Pol may be more appropriately characterised as part of the lemniscal pathway, while the medial MGB may be part of a third (polysensory) pathway, with characteristics of lemniscal and non-lemniscal areas. We document physiological properties of neurons in histologically identified areas of the MGB and Pol in the anaesthetised mouse, and present evidence in favour of a distinctive role for medial MGB in central auditory processing. In particular, medial MGB contains a greater proportion of neurons with short first-spike latencies and high response probabilities than either the ventral or dorsal MGB, despite having low spontaneous rates. Therefore, medial MGB neurons appear to fire more reliably in response to auditory input than neurons in even the lemniscal, ventral subdivision. Additionally, responses in the Pol are more similar to those in the ventral MGB than the dorsal MGB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Anesthesia / methods
  • Animals
  • Auditory Cortex / physiology*
  • Auditory Pathways / physiology
  • Brain Mapping / methods
  • Electron Transport Complex IV / metabolism
  • Geniculate Bodies / physiology
  • Hearing / physiology*
  • Male
  • Mice
  • Mice, Inbred CBA
  • Neurons / physiology
  • Probability
  • Thalamus / anatomy & histology
  • Thalamus / physiology*
  • Time Factors

Substances

  • Electron Transport Complex IV