Takigami S, Sunada H, Lukowiak K, Kuzirian AM, Alkon DL, Sakakibara M. Protein kinase C mediates memory consolidation of taste avoidance conditioning in Lymnaea stagnalis.
Neurobiol Learn Mem 2014;
111:9-18. [PMID:
24613854 DOI:
10.1016/j.nlm.2014.02.011]
[Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 02/05/2014] [Accepted: 02/23/2014] [Indexed: 11/25/2022]
Abstract
In Lymnaea stagnalis, in order to obtain a 10 min short-term memory (STM) of taste avoidance conditioning (TAC) at least 10 paired presentations of a conditioned stimulus (CS), sucrose, and an unconditioned stimulus (US), tactile stimulation to the animal's head, are required. Pre-exposure of snails to the protein kinase C (PKC) α and ε activator bryostatin (Bryo) facilitated STM formation in that only 5 paired CS-US trials were required. Typically 20 paired presentations of the CS-US are required for formation of STM and LTM. However, 20 paired presentations do not result in STM or LTM if snails are pre-incubated with a PKC inhibitor, Ro-32-0432. We also found that LTM lasting longer than 48 h was acquired with Bryo incubation for 45 min even after termination of the conditioning paradigm. These data suggest that activation of the α and ε isozymes of PKC is crucially involved in the formation of LTM and provide further support for a mechanism that has been conserved across the evolution of species ranging from invertebrate molluscs to higher mammals.
Collapse