*2.4. Treatment*

The rats were treated icv. in a volume of 2 μL over 30 s using a Hamilton microsyringe (Merck KGaA, Darmstadt, Germany). The doses applied were 0.1 or 1 μg of Kp-8 dissolved in 0.9% saline. Control animals were injected with 2 μL of 0.9% saline alone. The animals were treated 30 min prior to the behavioral tests. Collection of trunk blood for LH ELISA, corticosterone ELISA and serum corticosterone measurement were carried out 15 min and 30 min after icv. treatment, respectively.
