Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (UMR5287)

Aquitaine Institute for Cognitive and Integrative Neuroscience

Université de Bordeaux

Zone nord Bat 2 2ème étage
146, rue Léo Saignat
33076 Bordeaux cedex


Supervisory authorities

CNRS Ecole Pratique des Hautes Etudes Université de Bordeaux

Our partners

Neurocampus Unitéde Formation de Biologie


GDR Robotique GDR Mémoire GDR Multi-électrodes


Home > News

Thalamocortical projections uncovered

by Wolff - published on

Thalamocortical projections uncovered

Parallel inputs from the mediodorsal thalamus to the prefrontal cortex in the Rat.
Alcaraz F, Marchand AR, Courtand G, Coutureau E, & Wolff M

Eur J Neurosci. 2016 Jun 20. doi: 10.1111/ejn.13316. [Epub ahead of print]

In this study the DECAD team examined the architecture of the thalamocortical projections arising from the mediodorsal thalamus by mean of retrograde tracers injected in the dorsomedial, ventromedial (dm- and vmPFC) and the orbitofrontal cortex (OFC). These projections are currently thought to be critical for adaptive functions and were assessed by both qualitative and semi-quantitative analyses. A critical feature of the resulting thalamic labeling was that essentially separated neuronal populations are the source of three parallel pathways (B and C), which calls for a more specific focus on each of these pathways for future functional studies.

There is a growing interest in determining the functional contribution of thalamic inputs to cortical functions. In the context of adaptive behaviors, identifying the precise role of the mediodorsal thalamus (MD) in particular remains difficult despite the large amount of experimental data available. A better understanding of the thalamocortical connectivity of this region may help to capture its functional role. To address this issue, the present study focused exclusively on the specific connections from the MD to the prefrontal cortex (PFC) by mean of direct comparisons of labeling produced by single and dual injections of retrograde tracers in the different subdivisions of the PFC in the Rat. We show that at least three parallel and essentially separate thalamocortical pathways originate from the MD, as follows: projections to the dorsal (1) and the ventral (2) subdivisions of the mPFC follow a mediolateral topography at the thalamic level (i.e. medial thalamic neurons target the mPFC ventrally whereas lateral thalamic neurons project dorsally), whereas a considerable innervation to the OFC (3) includes thalamic cells projecting to both the lateral and the ventral OFC subdivisions. These observations provide new insight on the functions of the MD and suggest a specific focus on each of these pathways for future functional studies.