New publication on dopamine transmission in stress-coping behavior

We recently published a paper on a role of neurotransmitter dopamine in stress-coping behavior in Journal of Neuroscience.

Our publication in the Journal of Neurosience

When the animals encounter the environmental threat as stressor, we can think of two distinct strategies to cope with it. One is to try to overcome it by exploring actively and be against it, the other is to avoid and refrain from being close to it passively. Active and passive coping of the stress would be the basis to determine the behavioral strategies upon exposure to the stressor. Since maladaptation to the stress predispose the psychiatric disorders such as depression and anxiety, understanding the molecular mechanism underlying it is indispensable for the development of therapeutic intervention for them.

To address this, we focused on neurotransmitter dopamine which plays pivotal roles in decision making and reinforcement of the behaviors. We developed a fine carbon fiber electrode to scan the brain region called nucleus accumbens to examine how the dopamine release change when the mice changed stress-coping behaviors under the inescapable stress such as tail suspension. We found that reduction of dopamine release in this area precede the initation of escape behavior, implicating the dopaminergic transmission to the decision making under the stress.

Sub-milli second measurement of extracellular dopamine by fast scanning cyclic voltammetry

To check the causal effect of reduced dopamine release on mouse behaviors, we took two indepdent strategies. Optogenetic inhibitoin of dopaminergic fibers in the nucleus accumbens allowed inhibition of dopamine release at any time you want thru illumination of blue light.

Optogenetic manupulatin of the dopaminergic pathway

Another tool we used this time is CRISPR/Cas9 which deletes the receptors for dopaminergic transmission efficiently in the mouse brain by way of viral vector.

In vivo genome editing of dopaminergic receptors by CRISPR/Cas9 technology

Both experiments proved that impaired dopaminergic transmission caused induction of escape behavior during tail suspension stress. Through this study, we are pleased to establish three important tools which must be useful for futre study: fast scanning cyclic voltammetry, optogenetics and CRISPR/Cas9.

I hope to discuss these new tools in the post comming soon.

#Neurobiology #Hiroshima #Brain #神経 #広島 #脳

相澤 秀紀
相澤 秀紀
教授

宮城県出身、博士(医学、千葉大学大学院)。精神科での経験を背景に神経解剖学・生理学を活かした研究で疾患の病態生理に迫りたい。

Wanpeng Cui
Wanpeng Cui
Postdoc

相澤ラボでの学位取得後、広島大学での助教を経て現在米国へ留学中。神経科学の研究を発展させています。

伊藤日加瑠
伊藤日加瑠
准教授

米国留学より帰国後に広島大学助教として研究室に参加。その後、東京医科歯科大学助教を経て香川大学准教授に就任。細胞生物学から動物行動学まで幅広い手法をもとに動物行動の基盤を明らかにしようとしています。

Meina Zhu
Meina Zhu
Postdoc

中国で神経内科医として活躍後、広島大学大学院でうつ病の分子機構を研究し、学位を取得しました。

中野高志
中野高志
准教授

計算論的神経科学を背景に理論解析から生物実験など幅広い研究を展開する研究者。広島大学助教を経て、現在は藤田医科大学准教授として活躍 いています。