Species‐specific diversity in the anatomical and physiological organisation of the BNST‐VTA pathway. (28th March 2017)

• Record Type: Journal Article
• Authors: Kaufling, Jennifer; Girard, Delphine; Maitre, Marlène; Leste‐Lasserre, Thierry; Georges, François
• Editors: Foxe, John
• Is Part Of: European journal of neuroscience. Volume 45:Number 9(2017)
• Page Start: 1230
• Page End: 1240
• Publication Date: 2017-03-28
• Subjects: dopamine -- mice -- rat; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.13554
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: The anteromedial part of the bed nucleus of the stria terminalis (amBNST) is a limbic structure innervating the ventral tegmental area (VTA) that is remarkably constant across species. The amBNST modulates fear and anxiety, and activation of VTA dopamine (DA) neurons by amBNST afferents seems to be the way by which stress controls motivational states associated with reward or aversion. Because fear learning and anxiety states can be expressed differently between rats and mice, we compared the functional connectivity between amBNST and the VTA‐DA neurons in both species using consistent methodological approaches. Using a combination of in vivo electrophysiological, neuroanatomical tracing and laser capture approaches we explored the BNST influences on VTA‐DA neuron activity. First, we characterised in rats the molecular phenotype of the amBNST neurons projecting to the VTA. We found that this projection is complex, including both GABAergic and glutamatergic neurons. Then, VTA injections of a conventional retrograde tracer, the β‐sub‐unit of the cholera toxin (CTB), revealed a stronger BNST‐VTA projection in mice than in rats. Finally, electrical stimulations of the BNST during VTA‐DA neuron recording demonstrated a more potent excitatory influence of the amBNST on VTA‐DA neuron activity in rats than in mice. These data illustrate anatomically, but also functionally, a significant difference between rats and mice in the amBNST‐VTA pathway. More generally, together with previous findings, our research highlights the importance of species differences for the interpretation and the generalisation of research data. Abstract : Using consistent anatomical, molecular, and electrophysiological approaches we compare, in rats and mice, the functional connectivity between anteromedial part of the bed nucleus of the stria terminalis (amBNST) and dopaminergic neurons in the ventral tegmental area (VTA), a projection especially implicated in fear and anxiety. We found that this complex projection includes both GABAergic and glutamatergic neurons, a denser BNST‐VTA projection in mice than rats, and a more potent excitatory influence of the amBNST on VTA‐DA neuron activity in rats than in mice. This study provides new evidence on rodent interspecies differences in this projection, and has important implications for understanding the processing of anxiogenic information, and further highlights the importance of taking into account the choice of animal model for experimental design and interpretation.