Using 11C-raclopride PET we demonstrated increased endogenous dopamine release in the ventral striatum during Yoga Nidra meditation
Yoga Nidra is characterized by a depressed level of desire for action, associated with decreased blood flow in prefrontal, cerebellar and subcortical regions, structures thought to be organized in open loops subserving executive control
In the striatum, dopamine modulates excitatory glutamatergic synapses of the projections from the frontal cortex to striatal neurons, which in turn project back to the frontal cortex via the pallidum and ventral thalamus
The present study was designed to investigate whether endogenous dopamine release increases during loss of executive control in meditation
Participants underwent two 11C-raclopride PET scans: one while attending to speech with eyes closed, and one during active meditation
The tracer competes with endogenous dopamine for access to dopamine D2 receptors predominantly found in the basal ganglia
During meditation, 11C-raclopride binding in ventral striatum decreased by 7
This corresponds to a 65% increase in endogenous dopamine release
The reduced raclopride binding correlated significantly with a concomitant increase in EEG theta activity, a characteristic feature of meditation
All participants reported a decreased desire for action during meditation, along with heightened sensory imagery
The level of gratification and the depth of relaxation did not differ between the attention and meditation conditions
Here we show increased striatal dopamine release during meditation associated with the experience of reduced readiness for action
It is suggested that being in the conscious state of meditation causes a suppression of cortico-striatal glutamatergic transmission
To our knowledge this is the first time in vivo evidence has been provided for regulation of conscious states at a synaptic level
The practice of yoga during pregnancy seems to improve birth weight and reduce prematurity and overall complications
Shamanthakamani Narendran, from the Vivekananda Yoga Research Foundation in Bangalore, and colleagues studied 169 pregnant women trained in the integrated approach to yoga and in 166 “controls” who received routine prenatal care
The yoga training included various loosening exercises, postures (”asanas”), relaxation, deep breathing exercises (”pranayamas”), and meditation, which was practiced for 1 hour daily
Fourteen percent of deliveries were premature in the yoga group compared with 29 percent in the controls
Rates of pregnancy-related high blood pressure were also lower in the yoga group
Possible mechanisms whereby yoga improves pregnancy outcomes include increased blood flow to the placenta, decreased transfer of maternal stress hormones, and decreased premature release of hormones that trigger the onset of labor
Improvement in hand grip strength in normal volunteers and rheumatoid arthritis patients following yoga training
The present study aimed at assessing the effects of a set of yoga practices on normal adults (n = 37), children (n = 86), and patients with rheumatoid arthritis (n = 20)
An equal number of normal adults, children, and patients with rheumatoid arthritis who did not practice yoga were studied under each category, forming respective control groups
Yoga and control group subjects were assessed at baseline and after varying intervals, as follows, adults after 30 days, children after 10 days and patients after 15 days, based on the duration of the yoga program, which they attended, which was already fixed
Hand grip strength of both hands, measured with a grip dynamometer, increased in normal adults and children, and in rheumatoid arthritis patients, following yoga, but not in the corresponding control groups, showing no re-test effect
Adult female volunteers and patients showed a greater percentage improvement than corresponding adult males
This gender-based difference was not observed in children
Hence yoga practice improves hand grip strength in normal persons and in patients with rheumatoid arthritis, though the magnitude of improvement varies with factors such as gender and age
Ten healthy, untrained volunteers (nine females and one male), ranging in age from 18-27 years, were studied to determine the effects of hatha yoga practice on the health-related aspects of physical fitness, including muscular strength and endurance, flexibility, cardiorespiratory fitness, body composition, and pulmonary function
Subjects were required to attend a minimum of two yoga classes per week for a total of 8 weeks