Opening of shortcut circuits between visual and retrosplenial granular cortices of rats.
Traveling neural signals may try to find suitable paths of propagation in cortical circuits. We examined the behavior of electrically evoked signals from primary visual cortex (Oc1) to granular retrosplenial cortex (RSG) in rat brain slices under caffeine application. With continued electrical stimulation, evoked signals propagated from Oc1 to RSG along the upper layer of the secondary visual cortex (Oc2) and agranular retrosplenial cortex (RSA), but on further continuation of stimulation, a new shortcut pathway along the deep layer between Oc2 and RSG was opened. Circuitry changes reduced the signal traveling time by about 40 ms. Cortical neural circuits between Oc1 and RSG may thus have the ability to open a shortcut circuit in a use-dependent manner.
Yoshimura
Hiroshi
H
Department of Oral and Maxillofacial Surgery, Kanazawa Medical University, Uchinada-cho, Kanazawa, Ishikawa 920-0293, Japan. hyoshimu@kanazawa-med.ac.jp
Mashiyama
Yuichi
Y
Kaneyama
Keiseki
K
Nagao
Toshikazu
T
Segami
Natsuki
N
D000818:Animals; D000831:Animals, Newborn; D004558:Electric Stimulation / Q000379:methods; D005071:Evoked Potentials / Q000502:physiology* / Q000528:radiation effects; D006179:Gyrus Cinguli / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D051381:Rats; D017208:Rats, Wistar; D013057:Spectrum Analysis; D013997:Time Factors; D014793:Visual Cortex / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology*; D014795:Visual Pathways / Q000033:anatomy & histology / Q000502:physiology*