Different forms of effective connectivity in primate frontotemporal pathways

Nat Commun. 2015 Jan 23:6:6000. doi: 10.1038/ncomms7000.

Abstract

It is generally held that non-primary sensory regions of the brain have a strong impact on frontal cortex. However, the effective connectivity of pathways to frontal cortex is poorly understood. Here we microstimulate sites in the superior temporal and ventral frontal cortex of monkeys and use functional magnetic resonance imaging to evaluate the functional activity resulting from the stimulation of interconnected regions. Surprisingly, we find that, although certain earlier stages of auditory cortical processing can strongly activate frontal cortex, downstream auditory regions, such as voice-sensitive cortex, appear to functionally engage primarily an ipsilateral temporal lobe network. Stimulating other sites within this activated temporal lobe network shows strong activation of frontal cortex. The results indicate that the relative stage of sensory processing does not predict the level of functional access to the frontal lobes. Rather, certain brain regions engage local networks, only parts of which have a strong functional impact on frontal cortex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Auditory Cortex / physiology
  • Auditory Pathways / physiology*
  • Brain Mapping / methods
  • Frontal Lobe / pathology*
  • Image Processing, Computer-Assisted
  • Macaca mulatta
  • Magnetic Resonance Imaging / methods
  • Male
  • Nerve Net / physiology
  • Neural Pathways / physiology
  • Primates
  • Sound
  • Temporal Lobe / pathology*