Caffeine [HRP]

The aim of this study was to evaluate the effect of early prophylactic caffeine treatment on white matter development in very preterm infants using cerebral magnetic resonance imaging. A total of 194 preterm infants (<= 32 weeks gestational age) were randomly assigned to the caffeine (n = 96) or placebo (n = 93) treatment group and administered with either caffeine or placebo within 72 h after birth. Cerebral magnetic resonance imaging, including diffuse tensor imaging examination, was performed at 34-36 weeks of corrected gestational age, and the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured. In total, 160 infants were included in the final analysis, including 80 cases in the placebo group and 80 cases in the caffeine group. There were fewer instances of apnea of prematurity and shorter assisted ventilation times for infants in the caffeine group compared to the placebo group (p < 0.05). Infants in the caffeine group had significantly higher FA values in white matter, including the posterior limb of the internal capsule, the corpus callosum, the frontal, occipital, and parietal white matter, the cerebellum, and the cerebral peduncle, compared to infants in the placebo group. ADC values in the above white matter areas were significantly reduced in the caffeine group. However, there were no significant differences regarding the FA and ADC in the gray matter between the two groups. These results demonstrate that early administration of caffeine improves white matter micro-structural development in preterm infants, but with no significant effect on short-term complications related to prematurity.

By reducing the cerebral blood flow and thereby increasing the resting deoxyhaemoglobin concentration, many human studies have shown that caffeine has a beneficial effect on enhancing the magnitude of blood-oxygenation-level-dependent (BOLD) responses. However, the effect of caffeine on BOLD responses in animals under anaesthesia has not been demonstrated. In this study, we aimed to determine the effect of systemic caffeine administration on BOLD responses in rats under alpha-chloralose. By applying electric whisker pad stimulation to male Sprague-Dawley rats, we performed fMRI measurements before and after the caffeine injection (40 mg/kg,n = 7) or an equivalent volume of saline (n = 6) at 7T. To understand the potential perturbation of animal physiology during stimulation, arterial blood pressure was measured in a separate group of animals (n = 3) outside the scanner. Caffeine significantly decreased baseline BOLD signals (p = .05) due to the increased deoxyhaemoglobin level. Both BOLD responses and t-values in the primary somatosensory cortex were significantly increased (bothp < .05). The blood pressure changed insignificantly (p > .05). No significant differences in BOLD responses and t-values were observed in the control condition of saline injection (bothp > .05). These findings suggested that, although the cerebral activity was lower under alpha-chloralose anaesthesia, the higher level of deoxygemoglobin at the baseline under the caffeinated condition can benefit the magnitude of BOLD responses in rats. These findings suggest that animal models might serve as potential platforms for further caffeine-related fMRI research studies.