Heterogeneous properties of central lateral and parafascicular thalamic synapses in the striatum.

Ellender TJ
Harwood J
Kosillo P
Capogna M
Bolam JP
Scientific Abstract

To understand the principles of operation of the striatum it is critical to elucidate the properties of the main excitatory inputs from cortex and thalamus, as well as their ability to activate the main neurons of the striatum, the medium spiny neurons (MSNs). As the thalamostriatal projection is heterogeneous, we set out to isolate and study the thalamic afferent inputs to MSNs using small localized injections of adeno-associated virus carrying fusion genes for channelrhodopsin-2 and YFP, in either the rostral or caudal regions of the intralaminar thalamic nuclei (i.e. the central lateral or parafascicular nucleus). This enabled optical activation of specific thalamic afferents combined with whole-cell, patch-clamp recordings of MSNs and electrical stimulation of cortical afferents, in adult mice. We found that thalamostriatal synapses differ significantly in their peak amplitude responses, short-term dynamics and expression of ionotropic glutamate receptor subtypes. Our results suggest that central lateral synapses are most efficient in driving MSNs to depolarization, particularly those of the direct pathway, as they exhibit large amplitude responses, short-term facilitation and predominantly express postsynaptic AMPA receptors. In contrast, parafascicular synapses exhibit small amplitude responses, short-term depression and predominantly express postsynaptic NMDA receptors, suggesting a modulatory role, e.g. facilitating Ca(2+)-dependent processes. Indeed, pairing parafascicular, but not central lateral, presynaptic stimulation with action potentials in MSNs, leads to NMDA receptor- and Ca(2+)-dependent long-term depression at these synapses. We conclude that the main excitatory thalamostriatal afferents differ in many of their characteristics and suggest that they each contribute differentially to striatal information processing.

Citation

2013.J. Physiol. (Lond.), 591(1):257-72.

More Like This
Publication
Garas FN, Kormann E, Shah RS, Vinciati F, Smith Y, Magill PJ, Sharott A
2018. J. Comp. Neurol., 526(5):877-898.
Unit Publication
Publication
Pristerà A, Lin WY, Kaufmann AK, Brimblecombe KR, Threlfell S, Dodson PD, Magill PJ, Fernandes C, Cragg SJ, Ang SL
2015.Proc. Natl. Acad. Sci. U.S.A., 112(35):E4929-38.
Unit Publication
Publication
Blaesse P, Goedecke L, Bazelot M, Capogna M, Pape HC, Jüngling K
2015.J. Neurosci., 35(19):7317-25.
Unit Publication
Publication
Bogacz R, Martin Moraud E, Abdi A, Magill PJ, Baufreton J
2016.PLoS Comput. Biol., 12(7):e1005004.
Unit Publication
Publication
Tan H, Debarros J, He S, Pogosyan A, Aziz TZ, Huang Y, Wang S, Timmermann L, Visser-Vandewalle V, Pedrosa D, Green AL, Brown P
2019. Brain Stimul., 12(4):858-867.
Unit Publication