neurosciencestuff:

New research sheds light on neuronal communication

Researchers at the Max Planck Florida Institute for Neuroscience
have uncovered a critical molecule that regulates synaptic transmission

Synaptic proteins and neuronal transmission

A synapse consists of a presynaptic terminal of one neuron and a
postsynaptic terminal of another. The presynaptic terminal stores
vesicles containing neurotransmitters, while the postsynaptic terminal
contains neurotransmitter receptors. A dense collection of proteins is
present in these terminals, however the functional role of many of these
proteins remains unknown.

In particular, the G-protein-coupled receptor kinase-interacting
proteins (GITs) exert a critical control in synaptic transmission, since
deletions of these proteins are lethal or cause sensory deficits and
cognitive impairments in mice. In particular, GIT proteins and the
pathways they regulate have been implicated in neurological disorders
such as Attention Deficit Hyperactivity Disorder (ADHD) and Huntington’s
Disease. Several studies have demonstrated the role of GITs in the
postsynaptic terminal, but very little is known about their role in the
presynaptic terminal. Researchers in Samuel Young Jr.’s research team at
the Max Planck Florida Institute for Neuroscience set out to
investigate the role of GITs in the giant synapse, the calyx of Held, of
the auditory system – the optimal model to study the presynaptic
terminal independently from the postsynaptic terminal.

New findings

In their December publication in Neuron,
Drs. Samuel Young Jr. and Mónica S. Montesinos and collaborators report
for the first time that GIT proteins are critical presynaptic
regulators of synaptic strength. This study uncovers previously unknown
distinct roles for GIT1 and GIT2 in regulating neurotransmitter release
strength, with GIT1 as a specific regulator of presynaptic release
probability. This regulation is likely to contribute to the disruptions
in neural circuit functions leading to sensory disorders, memory and
learning impairment and other neurological disorders.

Future Directions

Future studies of Dr. Samuel Young Jr.’s lab will resolve the
mechanisms by which GITs regulate synaptic strength and their roles in
the early stages of auditory processing and neurological diseases. “Our
work brings significant insight into the understanding of how neuronal
communication is regulated, which is essential to understand the
cellular and molecular mechanisms of information processing by neuronal
circuits and the role of these proteins in the development of
neurological diseases,” explained Dr. Young.

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