Figure 1: Comparative analysis of DG images of DCX-immunoperoxidase-labelled cells in S. undulatus in different functional states: (a) normothermic summer animal; (b) normothermic winter animal; (c) 2.5 h provoked arousal; (d) hibernation. Intensive DCX labelling of immature granule cell dendritic tree was revealed in normothermic summer animals (a) in contrast to winter animals (b–d). Solid arrows show DCX-labelled dendritic trees and their retraction in hibernating state. Open arrows show there is significant retraction of mossy fibres in hibernating S. undulatus (d) in comparison to summer animals (a): (e) DCX labelling of neurons in Layer II of entorhinal cortex in summer animal (open arrows). AD: apical dendrite of granule cell; BV: blood vessel; IGCs: immature granule cells; SGZ: subgranular zone of DG.