172 LeDOUX A STM LTM ■sTM LTM Vchicle Figure7 Blockade of protein synthesis (with anisomycin),protein kinase A(with Rp PS),or mitogen-activ or Pavlovian fear conditioning and does no houl be noedFirsthou plasticity n the amyg dala appears to be required for Pavlovian fear conditioning to occur,the site of172 LeDOUX Figure 7 Blockade of protein synthesis (with anisomycin), protein kinase A (with Rp￾cAMPS), or mitogen-activated protein kinase (with PD098059) interferes with the expres￾sion of long-term memory (LTM), but not short-term memory (STM), for fear conditioning in rats. Drugs were administered intraventricularly immediately after conditioning, and fear respones were tested 24 h later while the rats were drug free. Based on Schafe et al (1999). learning and not on processes that occur after learning (Wilensky et al 1999). The amygdala thus seems to be essential for Pavlovian fear conditioning and does not modulate its own learning. Two additional points should be noted. First, although plasticity in the amyg￾dala appears to be required for Pavlovian fear conditioning to occur, the site of long-term memory storage is not known. It is possible that the storage is in the amygdala itself or, alternatively, that the storage is distributed and involves inter-