**6. Acknowledgment**

ESF project No. 2009/0217/1DP/1.1.1.2.0/09/APIA/VIAA/031; Latvian Science Council grant: No.10.0030. Center for Neuroscience and Cell Biology (CNC), and Center for Marine and Environmental Research (IMAR-CMA) of the University of Coimbra, Portugal.
