Graphomotor memory in Exner's area enhances word learning in the blind.

Handwriting is thought to impede vocabulary learning in sighted adults because the motor execution of writing interferes with efficient audiovisual processing during encoding. However, the motor memory of writing may facilitate adult word learning when visual sensory inputs are severely restricted. Using functional MRI, we show that late-blind participants, but not sighted participants, learned novel words by recruiting the left dorsal premotor cortex known as Exner's writing area and its functional coupling with the left hippocampus. During later recall, the phonological and semantic contents of these words are represented in the activation patterns of the left hippocampus as well as in those of left frontotemporal language areas. These findings suggest that motor codes of handwriting help blind participants maintain word-form representations during learning and retrieval. We propose that such reliance on the motor system reflects a broad architecture of the cerebral language network which encompasses the limb motor system as a hardwired component.

Acupuncture stimulates the release of serotonin, but not dopamine, in the rat nucleus accumbens.

Acupuncture has been introduced as one of the available therapies widely used in alternative medicine, but it has not achieved widespread acceptance with scientific evidence. Furthermore there are still many unanswered questions about the basic mechanisms of acupuncture. To investigate the neuropharmacological mechanisms of oriental acupuncture, we studied the acupuncture-induced changes of in vivo monoamine release in the rat brain. A microdialysis guide cannula was implanted into the nucleus accumbens (ACC), which plays an important role in the brain reward system. Acupuncture treatment at the unilateral or bilateral Shenshu (bladder urinary channel 23) acupoints, located on the both sides of the spinous processes on the lower back, was carried out for 60 min in freely moving rats, and the dopamine (DA) and serotonin (5-HT) contents of the microdialysates in the ACC were measured simultaneously. In rats subjected to acupuncture at bilateral Shenshu acupoints, increases of 5-HT release in the ACC were observed at 20 min of acupuncture treatment and continued until 40 min after acupuncture was ended. Acupuncture at a unilateral Shenshu acupoint increased the release of 5-HT at 20 min compared with that in the sham-control group. Five-HT release returned to the baseline level at 120 min. The effects of acupuncture at bilateral Shenshu acupoints on the release of 5-HT in the ACC were greater than that of unilateral acupuncture treatment. In contrast, DA release in the ACC was not changed following acupuncture treatment. Effective acupuncture increased and prolonged the activity of serotonergic neurons in the reward system pathway of the brain. This suggests that oriental acupuncture therapy may be effective for the treatment of emotional disorders, drug abuse and alcoholism.

Alterations in the function of cerebral dopaminergic and serotonergic systems following electroacupuncture and moxibustion applications: possible correlates with their antistress and psychosomatic actions.

Alterations in cerebral monoamines following application of electroacupuncture were investigated using conscious rats with and without application of restraining stress. The dopamine and serotonin levels were significantly decreased in the nucleus accumbens, caudate putamen, and lateral hypothalamus and increased in the dorsal raphe nucleus by restraining stress. On the other hand, application of electroacupuncture on the lumbar and hindlimb segments eliminated the above changes in dopamine, while the changes in serotonin were attenuated by lumbar and hindlimb electroacupuncture. However, the effects of hindlimb electroacupuncture were greater than those of lumbar electroacupuncture. These results clearly indicate that lumbar and hindlimb electroacupuncture stimulations have differential effects on brain monoaminergic neurons in rats exposed to restraining stress. Moxa burning stimulation was applied to the lumbar and hindlimb segments of rats without restraining stress. The dopamine level was significantly increased in the midbrain substantia nigra-ventrotegmental area by hindlimb moxibusion. On the other hand, the serotonin levels were significantly increased in the nucleus amygdala by lumber moxibusion and decreased in the nucleus accumbens by hindlimb moxibusion. The present results indicate that electroacupuncture applied to the lumbar and hindlimb segments has an antistress effect, while the application of moxibustion to the lumbar and hindlimb segments was likely to stimulate the functions of mesocortical and mesolimbic dopaminergic and serotonergic neurons. We suggest that functional alterations in cerebral dopaminergic and serotonergic neurons are involved in the clinical efficacy of electroacupuncture and moxibustion, especially because of their antistress and psychosomatic actions.

Pharmacological studies of alcohol susceptibility and brain monoamine function in stroke-prone spontaneously hypertensive rats (SHRSP) and stroke-resistant spontaneously hypertensive rats (SHRSR).

Differences of alcohol drinking behavior, brain dopamine (DA) and serotonin (5-HT) levels and releases in the striatum were investigated in stroke-prone spontaneously hypertensive rats (SHRSP) and age-matched stroke-resistant spontaneously hypertensive rats (SHRSR). Voluntary alcohol (EtOH) consumption in SHRSP rats increased at 1 and 2 hours in the 4 hour time access. In the DA level, SHRSP showed decreases in the caudate-putamen (C/P) and dorsal raphe nucleus (DRN) compared with in SHRSR. 5-HT levels in the C/P, ventral tegmental area-subtantia nigra (V/S) and DRN of the SHRSP were decreased compared with that in SHRSR. The basal extracellular levels of 5-HT release in the C/P were increased in SHRSP as compared with those in SHRSR. K(+)- or EtOH-induced DA and 5-HT releases in the C/P of the SHRSP were a lower magnitude than those in SHRSR. Increased basal extracellular 5-HT releases showing low levels of 5-HT in the C/P of SHRSP mean an abnormality of serotonergic neuronal functions in a normal physiological condition. Higher voluntary alcohol drinking behavior, so called lower susceptibility to EtOH, in the SHRSP may be associated with the degenerated rewarding system including the DRN. These results suggest that the hypertensive state causes the dysfunction in the striatum of the brain rewarding system and induces the risk for increasing alcohol consumption to compensate for the alteration of serotonergic neurons.