To adapt to their environment, animals subconsciously calculate how motor commands can be efficiently translated into the actual movements. Kawashima et al. discovered that serotonergic neurons in the dorsal raphe nucleus regulate the transient memory of such efficacy; thus, successive behaviors do not require repeated cumbersome readjustment of efficacy.

Abstract Substance P antagonists of the neurokinin-1 receptor type (NK1) are gaining growing interest as new antidepressant therapies. It has been postulated that these drugs exert this putative therapeutic effect without direct interactions with serotonin (5-HT) neurones. Our recent microdialysis experiment performed in NK1 receptor knockout mice suggested evidence of changes in 5-HT neuronal ...

Leptin is a secretory product of adipocytes that has been shown to affect food intake, metabolism, and reproduction. One site of leptin's action is the central nervous system, where the leptin receptor (Ob-R) messenger ribonucleic acid (mRNA) and protein are expressed in discrete areas. In both the rat and monkey, Ob-R mRNA has been localized in the Raphe nuclei of the brainstem. Neurons in the...

The forebrain serotonergic system is a crucial component in the control of impulsive behaviours. However, there is no direct evidence for natural serotonin activity during behaviours for delayed rewards as opposed to immediate rewards. Herein we show that serotonin efflux is enhanced while rats perform a task that requires waiting for a delayed reward. We simultaneously measured the levels of s...

Previous experience with stressors over which the subject has behavioral control blocks the typical behavioral consequences of subsequent exposure to stressors over which the organism has no behavioral control. The present experiments explored the involvement of the ventral medial prefrontal cortex (mPFCv) in mediating this "immunizing" or resilience producing effect of an initial experience wi...

In the preceding study a, we found that the effects of cervical dorsal column (DC) lesions were revealed by neurological and roughness-discrimination tests if the lesions destroyed at least 90 ~o of the total DC cross-sectional area. Since the dorsal columns form the major spinal input to the coronal somatosensory cortex12,13,18, unit recordings from this area should reflect the effects of DC l...

Amphetamine use is associated with dysphoric states, including heightened anxiety, that emerge within 24h of withdrawal from the drug. Corticotropin-releasing factor increases serotonin release in the central nucleus of the amygdala, and this neurochemical circuitry may play a role in mediating fear and anxiety states. We have previously shown that chronic amphetamine treatment increases cortic...

Activation of the dynorphin/κ-opioid receptor (KOR) system by repeated stress exposure or agonist treatment produces place aversion, social avoidance, and reinstatement of extinguished cocaine place preference behaviors by stimulation of p38α MAPK, which subsequently causes the translocation of the serotonin transporter (SERT, SLC6A4) to the synaptic terminals of serotonergic neurons. In the pr...