Physiological properties of Cantor coding-like iterated function system in the hippocampal CA1 network
- PDF / 358,716 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 94 Downloads / 192 Views
(0123456789().,-volV)(0123456789(). ,- volV)
BRIEF COMMUNICATION
Physiological properties of Cantor coding-like iterated function system in the hippocampal CA1 network Yasuhiro Fukushima1,2 Minoru Tsukada2
•
Yutaka Yamaguti3 • Shigeru Kuroda4 • Takeshi Aihara2,5 • Ichiro Tsuda6
•
Received: 15 June 2020 / Revised: 13 September 2020 / Accepted: 21 October 2020 Ó Springer Nature B.V. 2020
Abstract Cantor coding provides an information coding scheme for temporal sequences of events. In the hippocampal CA3–CA1 network, Cantor coding-like mechanism was observed in pyramidal neurons and the relationship between input pattern and recorded responses could be described as an iterated function system. However, detailed physiological properties of the system in CA1 remain unclear. Here, we performed a detailed analysis of the properties of the system related to the physiological basis of learning and memory. First, we investigated whether the system could be simply based on a series of on–off responses of excitatory postsynaptic potential (EPSP) amplitudes. We applied a series of three spatially distinct input patterns with similar EPSP peak amplitudes. The membrane responses showed significant differences in spatial clustering properties related to the iterated function system. These results suggest that existence of some factors, which do not simply depend on a series of on–off responses but on spatial patterns in the system. Second, to confirm whether the system is dependent on the interval of sequential input, we applied spatiotemporal sequential inputs at several intervals. The optimal interval was 30 ms, similar to the physiological input from CA3 to CA1. Third, we analyzed the inhibitory network dependency of the system. After GABAA receptor blocker (gabazine) application, quality of code discrimination in the system was lower under subthreshold conditions and higher under suprathreshold conditions. These results suggest that the inhibitory network increase the difference between the responses under sub- and suprathreshold conditions. In summary, Cantor coding-like iterated function system appears to be suitable for information expression in relation to learning and memory in CA1 network. Keywords Spatiotemporal coding Iterated function system Single neuron Hippocampus Patch-clamp recording
Introduction Contextual information, used by the brain for immediate response to the stimuli, is believed to be stored in the hippocampus structure in form of short-term-memory & Yasuhiro Fukushima [email protected] 1
Comprehensive Education Center, Kawasaki University of Medical Welfare, 288 Matsushima, Kurashiki, Okayama 700-0193, Japan
2
Tamagawa University Brain Science Institute, 6-1-1 Tamagawagakuen, Machida, Tokyo 194-8610, Japan
3
Faculty of Information Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-higashi, Higashiku, Fukuoka 811-0295, Japan
(Ekstorm and Ranganath 2018). In the hippocampus, it is possible to identify 3 different structures connected in a circuit system where the
Data Loading...
