On the Temporary Nature of Disruption of Fear-Potentiated Startle Following PKMζ Inhibition in the Amygdale

startle reflex task coupled with ZIP infusions into the basolateral amygdala (BLA), and tested retention impairments under a variety of conditions. One of the factors that will affect the chance of recovery is how robust the amnesia is. When the performance impairment is small, the probability of recovery is high (Davis and Rosenzweig, 1978). The dose used by the authors was four times lower that used in 9 of 10 studies on the topic (Serrano et al., 2008; Migues et al., 2010). Therefore, in all likelihood less amnesia will be induced increasing the probability that amnesia will recover (Davis and Rosenzweig, 1978). It would be important to see if using the higher doses as used by majority of scientists in the field would lead to a long-term impairment in the paradigm used by Parson and Davis. The authors report that 1 day after receiving ZIP infusions, animals show decreased levels of performance compared to animals receiving vehicle infusions suggesting that the animals were amnesic. However with a longer interval between injection and testing, the groups show the same levels of freezing (suggesting that the animals were no longer amnesic). In order to conclude that recovery from either extinction (Bouton, 1993) or amnesia (Kohlenberg and Trabasso, 1968; Miller and Springer, 1974) has occurred, it is crucial to demonstrate that performance has significantly increased or “recovered” over time. No such comparison was performed. Instead, t-tests between vehicle and ZIP groups at each time point are reported. The authors interpret significant statistical difference as evidence for amnesia and its absence as evidence for the lack of amnesia. This might be acceptable if the baseline responding of animals in the control group did not change as well. Unfortunately, reduced performance of vehicle groups are more striking than any putative increase in performance in ZIP groups. In some cases (their Figure 3B) the levels of responding for the vehicle group was reduced by 75% whereas the increase in On the temporary nature of disruption of fear-potentiated startle following PKMζ inhibition in the amygdale