Miyata Mariko    Department   School of Medicine, School of Medicine    Position   Professor and Division head
Language	English
Title	Cortical feedback activity regulates connection pattern of afferent lemniscal synapses in the somatosensory thalamus.
Conference	The 91st Annual Meeting of the Physiological Society of Japan
Conference Type	International society and overseas society
Presentation Type	Poster notice
Lecture Type	General
Publisher and common publisher	◎Narushima Madoka, Miyata Mariko
Date	2014/03/16
Venue (city and name of the country)	Kagoshima Univ., Kagosima, Japan
Summary	Plenty of studies revealed synaptic/molecular mechanisms for initial formation and neuronal activity-dependent refinement of synaptic connections in early development. However, mechanisms for subsequent maintenance of once established circuits in matured brain are not fully understood. In the sensory thalamus (VPm and dLGN), the sensory afferent synapses (lemniscal and retinogeniculate (RG) synapses) onto a thalamic neuron are maintained in an experience-dependent manner after developmental synapse elimination. A thalamic neuron receives two kinds of excitatory inputs from afferents and massive feedback corticothalamic (CT) inputs. Thus, the functional linkage between the two inputs may underlie the maintenance of thalamic afferent synapses. Recently we found that type 1 metabotropic glutamate receptor (mGluR1) plays a critical role in the experience-dependent maintenance of RG synapses (Narushima et al., in preparation). Because mGluR1 densely expressed at postsynaptic site of the feedback CT synapses, we hypothesized that cortical activity regulates maintenance of afferent synapses after maturation. Here we report that pharmacological manipulation of cortical activity triggered remodeling of lemniscal synapses. The results support the idea that CT feedback inputs heterosynaptically regulates maintenance of matured mono-innervation of afferent synapses in the sensory thalamus.