Abstract
The midbrain dopamine (mDA) system is involved in the control of cognitive and motor behaviors, and is associated with several psychiatric and neurodegenerative diseases. mDA neurons receive diverse afferent inputs and establish efferent connections with many brain areas. Recent studies have unveiled a high level of molecular and cellular heterogeneity within the mDA system with specific subsets of mDA neurons displaying select molecular profiles and connectivity patterns. During mDA neuron development, molecular differences between mDA neuron subsets allow the establishment of subset-specific afferent and efferent connections and functional roles. In this review, we summarize and discuss recent work defining novel mDA neuron subsets based on specific molecular signatures. Then, molecular cues are highlighted that control mDA neuron migration during embryonic development and that facilitate the formation of selective patterns of efferent connections. The review focuses largely on studies that show differences in these mechanisms between different subsets of mDA neurons and for which in vivo data is available, and is concluded by a section that discusses open questions and provides directions for further research.
Highlights
The dopamine system of the ventral midbrain can be subdivided into three main nuclei: substantia nigra pars compacta (SNc, A9), ventral tegmental area (VTA, A10), and retrorubral field (RRF, A8)
Experimental data show that reelin and its receptors are necessary for the correct tangential migration of a subset of SNc midbrain dopamine (mDA) neurons. It remains to be determined whether reelin influences SNc mDA neuron movement directly by acting as an attractant guidance cue, or whether it is required for the correct development of the guidance scaffolds used by these neurons for migration
medial forebrain bundles (MFBs), medial forebrain bundle; Str, striatum; HYP, hypothalamus; to Hb, indicates mDA fibers growing toward the habenula; MHO, midbrain–hindbrain organizer
Summary
The midbrain dopamine (mDA) system is involved in the control of cognitive and motor behaviors, and is associated with several psychiatric and neurodegenerative diseases. MDA neurons receive diverse afferent inputs and establish efferent connections with many brain areas. Recent studies have unveiled a high level of molecular and cellular heterogeneity within the mDA system with specific subsets of mDA neurons displaying select molecular profiles and connectivity patterns. During mDA neuron development, molecular differences between mDA neuron subsets allow the establishment of subsetspecific afferent and efferent connections and functional roles. We summarize and discuss recent work defining novel mDA neuron subsets based on specific molecular signatures. Molecular cues are highlighted that control mDA neuron migration during embryonic development and that facilitate the formation of selective patterns of efferent connections.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.