Qualitative and quantitative estimation of comprehensive synaptic connectivity in short- and long-term cultured rat hippocampal neurons with new analytical methods inspired by Scatchard and Hill plots

Journal Article · Fri Mar 18 04:00:00 EDT 2016 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/J.BBRC.2016.02.048· OSTI ID:22594282

Tanamoto, Ryo; Shindo, Yutaka; Niwano, Mariko ^[1]; Matsumoto, Yoshinori ^[2]; Miki, Norihisa ^[3]; Hotta, Kohji ^[1]; Oka, Kotaro ^[1]

---

1. Department of Biosciences and Informatics, Faculty of Science and Technology, Keio University (Japan)
2. Department of Applied Physics and Physico-Informatics, Faculty of Science and Technology, Keio University (Japan)
3. Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa, 223-8522 (Japan)

To investigate comprehensive synaptic connectivity, we examined Ca{sup 2+} responses with quantitative electric current stimulation by indium-tin-oxide (ITO) glass electrode with transparent and high electro-conductivity. The number of neurons with Ca{sup 2+} responses was low during the application of stepwise increase of electric current in short-term cultured neurons (less than 17 days in-vitro (DIV)). The neurons cultured over 17 DIV showed two-type responses: S-shaped (sigmoid) and monotonous saturated responses, and Scatchard plots well illustrated the difference of these two responses. Furthermore, sigmoid like neural network responses over 17 DIV were altered to the monotonous saturated ones by the application of the mixture of AP5 and CNQX, specific blockers of NMDA and AMPA receptors, respectively. This alternation was also characterized by the change of Hill coefficients. These findings indicate that the neural network with sigmoid-like responses has strong synergetic or cooperative synaptic connectivity via excitatory glutamate synapses. - Highlights: • We succeed to evaluate the maturation of neural network by Scathard and Hill Plots. • Long-term cultured neurons showed two-type responses: sigmoid and monotonous. • The sigmoid-like increase indicates the cooperatevity of neural networks. • Excitatory glutamate synapses cause the cooperatevity of neural networks.

• OSTI ID: 22594282
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 4 Vol. 471; ISSN BBRCA9; ISSN 0006-291X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BIOMEDICAL RADIOGRAPHY
CALCIUM IONS
ELECTRIC CURRENTS
ELECTRODES
IN VITRO
NERVE CELLS
NEURAL NETWORKS
RATS
RECEPTORS
STIMULATION
TIN OXIDES