Those who travel to mountain tops are half in love with themselves, and half in love with oblivion". Maybe, in the final analysis, it is all as simple as the notion expressed by the late Joe Tasker in the postscript to his book Savage Arena: that the business of climbing exerts a constant and magnetic curiousity.
Whereas promotion of stair climbing still exerted positive effects during those 2 weeks while the elevator signs were already removed, it remains uncertain whether those effects are maintained after a longer period.
For the first time, biologists have measured the force exerted by climbing snakes, using pressure sensors on a vertical pipe, wrapped in tennis grip.
However, the climbing fibre input continuously exerts an activity-dependent repression on parallel fibre synapses, thus confining them to the distal Purkinje cell dendritic domain.
In particular, spines in the proximal dendritic compartment of Purkinje cells are under a tonic repressive action exerted by climbing fibres.
These findings led to the hypotheses that: i) an activity-independent, intrinsic mechanism, promotes spine growth over the whole dendritic territory of Purkinje cells [22], [27], [28] and ii) an activity-dependent spine-pruning action is exerted by the climbing fibres near their synapses in the proximal dendrites [19], [24], [25], [29].
These findings led to the hypotheses that: i) an activity-independent, intrinsic mechanism promotes spine growth over the whole Purkinje cell dendritic territory [19], [27] and ii) an activity-dependent spine-pruning action is exerted by the climbing fibres in the territory surrounding their synapses as a kind of lateral inhibition [19], [39].
Our data suggest that Purkinje cell loss in the Inpp4awbl mutant is due to glutamate excitotoxicity initiated by the climbing fiber, and that Eaat4 may exert a protective effect.
As in Experiment 1, this demonstrates that rats in all groups were able to discriminate between different-sized rewards and to exert the effortful response (i.e. climbing a barrier).
In Experiment 2, animals had to exert additional effort to obtain the HR by climbing over a barrier (Rudebeck et al., 2006; Walton, Bannerman, Alterescu, & Rushworth, 2003; Walton et al., 2002).
