Gangadharan, Gireesh Shin, Jonghan Kim, Seong-Wook Kim, Angela Paydar, Afshin Kim, Duk-Soo Miyazaki, Taisuke Watanabe, Masahiko Yanagawa, Yuchio Kim, Jinhyun Kim, Yeon-Soo Kim, Daesoo Shin, Hee-Sup 2024-01-20T04:02:23Z 2024-01-20T04:02:23Z 2021-09-05 2016-06-07 0027-8424 https://pubs.kist.re.kr/handle/201004/123972 Exploratory drive is one of the most fundamental emotions, of all organisms, that are evoked by novelty stimulation. Exploratory behavior plays a fundamental role in motivation, learning, and well-being of organisms. Diverse exploratory behaviors have been described, although their heterogeneity is not certain because of the lack of solid experimental evidence for their distinction. Here we present results demonstrating that different neural mechanisms underlie different exploratory behaviors. Localized Ca(v)3.1 knockdown in the medial septum (MS) selectively enhanced object exploration, whereas the null mutant (KO) mice showed enhanced-object exploration as well as open-field exploration. In MS knockdown mice, only type 2 hippocampal theta rhythm was enhanced, whereas both type 1 and type 2 theta rhythm were enhanced in KO mice. This selective effect was accompanied by markedly increased excitability of septo-hippocampal GABAergic projection neurons in the MS lacking T-type Ca2+ channels. Furthermore, optogenetic activation of the septo-hippocampal GABAergic pathway in WT mice also selectively enhanced object exploration behavior and type 2 theta rhythm, whereas inhibition of the same pathway decreased the behavior and the rhythm. These findings define object exploration distinguished from open-field exploration and reveal a critical role of T-type Ca2+ channels in the medial septal GABAergic projection neurons in this behavior. English NATL ACAD SCIENCES CA2+ CHANNELS OSCILLATIONS RATS NOVELTY LESIONS MICE INTERNEURONS SUPPRESSES MODULATION EXPRESSION Medial septal GABAergic projection neurons promote object exploration behavior and type 2 theta rhythm Article 10.1073/pnas.1605019113 1 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, v.113, no.23, pp.6550 - 6555 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 113 23 6550 6555 scie scopus 000377155400057 2-s2.0-84973392504 Multidisciplinary Sciences Science & Technology - Other Topics Article CA2+ CHANNELS OSCILLATIONS RATS NOVELTY LESIONS MICE INTERNEURONS SUPPRESSES MODULATION EXPRESSION Ca(v)3.1 T-type Ca2(+) channel exploratory behaviors hippocampal theta rhythm medial septum septo-hippocampal GABAergic neurons