AUTHOR=Hosp Jonas A., Luft Andreas R.

TITLE=Dopaminergic Meso-Cortical Projections to M1: Role in Motor Learning and Motor Cortex Plasticity

JOURNAL=Frontiers in Neurology

VOLUME=Volume 4 - 2013

YEAR=2013

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2013.00145

DOI=10.3389/fneur.2013.00145

ISSN=1664-2295

ABSTRACT=Although the architecture of a dopaminergic (DA) system within the primary motor
cortex (M1) was well characterized anatomically, its functional significance remained
obscure for a long time. Recent studies in rats revealed that the integrity of
dopaminergic fibers in M1 is a prerequisite for successful acquisition of motor skills.
This essential contribution of DA for motor learning is plausible as it modulates M1
circuitry at multiple levels thereby promoting plastic changes that are required for
information storage: at the network level, DA increases cortical excitability and
enhances the stability of motor maps. At the cellular level, DA induces the expression
of learning related genes via the transcription factor c-fos. At the level of synapses,
DA is required for the formation of long-term potentiation (LTP), a mechanism that
likely is a fingerprint of a motor memory trace within M1. Dopaminergic fibers
innervating M1 originate within the midbrain, precisely the ventral tegmental area
(VTA) and the medial portion of substantia nigra (SN). Thus, they could be part of the
meso-cortico-limibic pathway – a network that provides information about saliency
and motivational value of an external stimulus and is commonly referred as