Samantha Cermak1, Qinglei Meng1, Kevin Peng1, Simone Baldwin1, Carlos A Mejías-Aponte1, Yihong Yang2, Hanbing Lu3. 1. Neuroimaging Research Branch, Histology Core, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, MD, 21224, USA. 2. Neuroimaging Research Branch, Histology Core, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, MD, 21224, USA. Electronic address: yihongyang@mail.nih.gov. 3. Neuroimaging Research Branch, Histology Core, National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, MD, 21224, USA. Electronic address: luha@mail.nih.gov.
Abstract
BACKGROUND: Transcranial magnetic stimulation (TMS) is an emerging neuromodulation tool. However, preclinical models of TMS are limited. OBJECTIVE: To develop a method for performing TMS in awake rats and to characterize neuronal response to TMS by mapping glucose uptake following TMS administration. METHODS: A headpost was implanted into rat skull serving as a refence to guide TMS target. Motor threshold measurement was used as the metric to assess the consistency in TMS delivery across animals and across sessions. Using a fluorescent glucose analogue (2-NBDG) as a marker of neuronal activity, we mapped glucose uptake in response to TMS of the rat motor cortex. RESULTS: The average motor threshold (n = 41) was 34.6 ± 6.3 % of maximum stimulator output (MSO). The variability of motor threshold across animals was similar to what has been reported in human studies. Furthermore, there was no significant difference in motor threshold measured across 3 separate days. Enhancement in fluorescent signals were TMS dose (power)-dependent, which centered around the motor cortex, covering an area medial-laterally 2 mm, rostral-caudally 4 mm at 55 % MSO, and 3 mm at 35 % MSO. The count of total cells with significant fluorescent signal was: 107 ± 23 (55 % MSO), 73 ± 11 (35 % MSO) and 42 ± 11 (sham, 5% MSO). CONCLUSIONS: Our method allows for consistent motor threshold assessment for longitudinal studies. Notably, cells with fluorescent signal enhancement were consistently aggregated in deep cortical layers, with minimal enhancement in superficial layers COMPARISONS WITH EXISTING METHOD(S): To our knowledge, this is the first study of focal TMS in awake rodents.
BACKGROUND: Transcranial magnetic stimulation (TMS) is an emerging neuromodulation tool. However, preclinical models of TMS are limited. OBJECTIVE: To develop a method for performing TMS in awake rats and to characterize neuronal response to TMS by mapping glucose uptake following TMS administration. METHODS: A headpost was implanted into rat skull serving as a refence to guide TMS target. Motor threshold measurement was used as the metric to assess the consistency in TMS delivery across animals and across sessions. Using a fluorescent glucose analogue (2-NBDG) as a marker of neuronal activity, we mapped glucose uptake in response to TMS of the rat motor cortex. RESULTS: The average motor threshold (n = 41) was 34.6 ± 6.3 % of maximum stimulator output (MSO). The variability of motor threshold across animals was similar to what has been reported in human studies. Furthermore, there was no significant difference in motor threshold measured across 3 separate days. Enhancement in fluorescent signals were TMS dose (power)-dependent, which centered around the motor cortex, covering an area medial-laterally 2 mm, rostral-caudally 4 mm at 55 % MSO, and 3 mm at 35 % MSO. The count of total cells with significant fluorescent signal was: 107 ± 23 (55 % MSO), 73 ± 11 (35 % MSO) and 42 ± 11 (sham, 5% MSO). CONCLUSIONS: Our method allows for consistent motor threshold assessment for longitudinal studies. Notably, cells with fluorescent signal enhancement were consistently aggregated in deep cortical layers, with minimal enhancement in superficial layers COMPARISONS WITH EXISTING METHOD(S): To our knowledge, this is the first study of focal TMS in awake rodents.
Authors: Stacy R Millon; Julie H Ostrander; J Quincy Brown; Anita Raheja; Victoria L Seewaldt; Nirmala Ramanujam Journal: Breast Cancer Res Treat Date: 2011-02 Impact factor: 4.872
Authors: Michelle R Madore; Eugenia Poh; Samuel John Bollard; Jesus Rivera; Joy Taylor; Jauhtai Cheng; Eric Booth; Monica Nable; Alesha Heath; Jerry Yesavage; Jennifer Rodger; M Windy McNerney Journal: J Neurosci Methods Date: 2021-06-17 Impact factor: 2.987
Authors: Aaro V Salminen; Stefan Clemens; Diego García-Borreguero; Imad Ghorayeb; Yuqing Li; Mauro Manconi; William Ondo; David Rye; Jerome M Siegel; Alessandro Silvani; John W Winkelman; Richard P Allen; Sergi Ferré Journal: Dis Model Mech Date: 2022-08-10 Impact factor: 5.732