Spontaneous Bursting Activity in the Developing Entorhinal Cortex

• DOI: 10.1523/jneurosci.1333-09.2009
• Publication Date: 2009-09-30T17:49:10Z
• Authors: Maxim G. Sheroziya; Oliver von Bohlen...; Klaus Unsicker; Alexei V. Egorov
• Keywords: Bursting; Riluzole; Entorhinal cortex; BAPTA

Periodic spontaneous activity represents an important attribute of the developing nervous system. The entorhinal cortex (EC) is a crucial component medial temporal lobe memory Yet, little known about in immature EC. Here, we investigated field potential (fp) and intrinsic firing patterns EC layer III principal neurons brain slices obtained from rats at first two postnatal weeks. A fraction spontaneously generated prolonged (2–20 s) voltage-dependent bursting activity. Prolonged bursts were dependent on extracellular concentration Ca 2+ ([Ca ] o ). Thus, reduction [Ca increased with by inducing regularly neurons. In 1 m , percentages showing 53%, 81%, 29% day 5 (P5)–P7, P8–P10, P11–P13, respectively. was blocked buffering intracellular BAPTA, Cd flufenamic acid (FFA), or TTX, suppressed nifedipine riluzole, suggesting that -sensitive nonspecific cationic current ( I CAN ) persistent Na + Nap underlie this effect. Indeed, 0.2–1 s suprathreshold step stimulus elicited terminated plateau these fp recordings P5–P7 showed periodic glutamate receptor-mediated events (sharp bursts) which FFA. Slow-wave network oscillations become dominant pattern P11–P13. We conclude characteristic feature might be involved neuronal maturation.