Tau reduction prevents Aβ-induced axonal transport deficits by blocking activation of GSK3β.

Axonal transport deficits in Alzheimer's disease (AD) are attributed to amyloid β (Aβ) peptides and pathological forms of the microtubule-associated protein tau. Genetic ablation of tau prevents neuronal overexcitation and axonal transport deficits caused by recombinant Aβ oligomers. Relevance of these findings to naturally secreted Aβ and mechanisms underlying tau's enabling effect are unknown.

On the positive and negative affective responses to cocaine and their relation to drug self-administration in rats.

Rationale: Acute cocaine administration produces an initial rewarding state followed by a dysphoric/anxiogenic "crash."

Objective: The objective of this study was to determine whether individual differences in the relative value of cocaine's positive and negative effects would account for variations in subsequent drug self-administration.

Methods: The dual actions of cocaine were assessed using a conditioned place test (where animals formed preferences for environments paired with the immediate rewarding effects of 1.