scholarly journals Dopamine promotes aggression in mice via ventral tegmental area to lateral septum projections

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Darshini Mahadevia ◽  
Rinki Saha ◽  
Alessia Manganaro ◽  
Nao Chuhma ◽  
Annette Ziolkowski-Blake ◽  
...  

AbstractSeptal-hypothalamic neuronal activity centrally mediates aggressive behavior and dopamine system hyperactivity is associated with elevated aggression. However, the causal role of dopamine in aggression and its target circuit mechanisms are largely unknown. To address this knowledge gap, we studied the modulatory role of the population- and projection-specific dopamine function in a murine model of aggressive behavior. We find that terminal activity of ventral tegmental area (VTA) dopaminergic neurons selectively projecting to the lateral septum (LS) is sufficient for promoting aggression and necessary for establishing baseline aggression. Within the LS, dopamine acts on D2-receptors to inhibit GABAergic neurons, and septal D2-signaling is necessary for VTA dopaminergic activity to promote aggression. Collectively, our data reveal a powerful modulatory influence of dopaminergic synaptic input on LS function and aggression, effectively linking the clinically pertinent hyper-dopaminergic model of aggression with the classic septal-hypothalamic aggression axis.

Author(s):  
Ya-Dong Li ◽  
Yan-Jia Luo ◽  
Wei Xu ◽  
Jing Ge ◽  
Yoan Cherasse ◽  
...  

Abstract The ventral pallidum (VP) regulates motivation, drug addiction, and several behaviors that rely on heightened arousal. However, the role and underlying neural circuits of the VP in the control of wakefulness remain poorly understood. In the present study, we sought to elucidate the specific role of VP GABAergic neurons in controlling sleep–wake behaviors in mice. Fiber photometry revealed that the population activity of VP GABAergic neurons was increased during physiological transitions from non-rapid eye movement (non-REM, NREM) sleep to either wakefulness or REM sleep. Moreover, chemogenetic and optogenetic manipulations were leveraged to investigate a potential causal role of VP GABAergic neurons in initiating and/or maintaining arousal. In vivo optogenetic stimulation of VP GABAergic neurons innervating the ventral tegmental area (VTA) strongly promoted arousal via disinhibition of VTA dopaminergic neurons. Functional in vitro mapping revealed that VP GABAergic neurons, in principle, inhibited VTA GABAergic neurons but also inhibited VTA dopaminergic neurons. In addition, optogenetic stimulation of terminals of VP GABAergic neurons revealed that they promoted arousal by innervating the lateral hypothalamus, but not the mediodorsal thalamus or lateral habenula. The increased wakefulness chemogenetically evoked by VP GABAergic neuronal activation was completely abolished by pretreatment with dopaminergic D1 and D2/D3 receptor antagonists. Furthermore, activation of VP GABAergic neurons increased exploration time in both the open-field and light–dark box tests but did not modulate depression-like behaviors or food intake. Finally, chemogenetic inhibition of VP GABAergic neurons decreased arousal. Taken together, our findings indicate that VP GABAergic neurons are essential for arousal related to motivation.


2018 ◽  
Author(s):  
Tatiana V Tarasova ◽  
Olga A Lytkina ◽  
Valeria V Goloborshcheva ◽  
Larisa N Skuratovskaya ◽  
Alexandr I Antohin ◽  
...  

Lesion of the dopaminergic neurons of the nigrostriatal system is a key feature of Parkinson's disease (PD). Alpha-synuclein is a protein that is a major component of Lewy bodies, histopathological hallmarks of PD, and is involved in regulation of dopamine (DA) neurotransmission. Previous studies of knockout mice have shown that inactivation of alpha-synuclein gene can lead to the reduction in number of DA neurons in the substantia nigra (SN). DA neurons of the SN are known to be the most affected in PD patients whereas DA neurons of neighboring ventral tegmental area (VTA) are much less susceptible to degeneration. Here we have studied the dynamics of changes in TH-positive cell numbers in the SN and VTA during a critical period of their embryonic development in alpha-synuclein knockout mice. This precise study of DA neurons during development of the SN revealed that not only is the number of DA neurons reduced by the end of the period of ontogenic selection, but that the way these neurons are formed is altered in alpha-synuclein knockout mice. At the same time, DA neurons in the VTA are not affected. Alpha-synuclein exerts a modulating effect on the formation of DA neurons in the SN and has no effect on the formation of DA neurons in VTA, the structure that is much less susceptible to degeneration in PD brain, suggesting a potential role of alpha-synuclein in the development of the population of DA neurons in substantia nigra.


2018 ◽  
Author(s):  
Tatiana V Tarasova ◽  
Olga A Lytkina ◽  
Valeria V Goloborshcheva ◽  
Larisa N Skuratovskaya ◽  
Alexandr I Antohin ◽  
...  

Lesion of the dopaminergic neurons of the nigrostriatal system is a key feature of Parkinson's disease (PD). Alpha-synuclein is a protein that is a major component of Lewy bodies, histopathological hallmarks of PD, and is involved in regulation of dopamine (DA) neurotransmission. Previous studies of knockout mice have shown that inactivation of alpha-synuclein gene can lead to the reduction in number of DA neurons in the substantia nigra (SN). DA neurons of the SN are known to be the most affected in PD patients whereas DA neurons of neighboring ventral tegmental area (VTA) are much less susceptible to degeneration. Here we have studied the dynamics of changes in TH-positive cell numbers in the SN and VTA during a critical period of their embryonic development in alpha-synuclein knockout mice. This precise study of DA neurons during development of the SN revealed that not only is the number of DA neurons reduced by the end of the period of ontogenic selection, but that the way these neurons are formed is altered in alpha-synuclein knockout mice. At the same time, DA neurons in the VTA are not affected. Alpha-synuclein exerts a modulating effect on the formation of DA neurons in the SN and has no effect on the formation of DA neurons in VTA, the structure that is much less susceptible to degeneration in PD brain, suggesting a potential role of alpha-synuclein in the development of the population of DA neurons in substantia nigra.


Author(s):  
Verónica Company ◽  
Abraham Andreu-Cervera ◽  
M. Pilar Madrigal ◽  
Belén Andrés ◽  
Francisca Almagro-García ◽  
...  

The fasciculus retroflexus is an important fascicle that mediates reward-related behaviors and is associated with different psychiatric diseases. It is the main habenular efference and constitutes a link between forebrain regions, the midbrain, and the rostral hindbrain. The proper functional organization of habenular circuitry requires complex molecular programs to control the wiring of the habenula during development. However, the mechanisms guiding the habenular axons toward their targets remain mostly unknown. Here, we demonstrate the role of the mesodiencephalic dopaminergic neurons (substantia nigra pars compacta and ventral tegmental area) as an intermediate target for the correct medial habenular axons navigation along the anteroposterior axis. These neuronal populations are distributed along the anteroposterior trajectory of these axons in the mesodiencephalic basal plate. Using in vitro and in vivo experiments, we determined that this navigation is the result of netrin 1 attraction generated by the mesodiencephalic dopaminergic neurons. This attraction is mediated by the receptor deleted in colorectal cancer (DCC), which is strongly expressed in the medial habenular axons. The increment in our knowledge on the fasciculus retroflexus trajectory guidance mechanisms opens the possibility of analyzing if its alteration in mental health patients could account for some of their symptoms.


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