Author(s): Nehlig A, Daval JL, Debry G
Caffeine is the most widely consumed centralnervous-system stimulant. Three main mechanisms of action of caffeine on the central nervous system have been described. Mobilization of intracellular calcium and inhibition of specific phosphodiesterases only occur at high non-physiological concentrations of caffeine. The only likely mechanism of action of the methylxanthine is the antagonism at the level of adenosine receptors. Caffeine increases energy metabolism throughout the brain but decreases at the same time cerebral blood flow, inducing a relative brain hypoperfusion. Caffeine activates noradrenaline neurons and seems to affect the local release of dopamine. Many of the alerting effects of caffeine may be related to the action of the methylxanthine on serotonine neurons. The methylxanthine induces dose-response increases in locomotor activity in animals. Its psychostimulant action on man is, however, often subtle and not very easy to detect. The effects of caffeine on learning, memory, performance and coordination are rather related to the methylxanthine action on arousal, vigilance and fatigue. Caffeine exerts obvious effects on anxiety and sleep which vary according to individual sensitivity to the methylxanthine. However, children in general do not appear more sensitive to methylxanthine effects than adults. The central nervous system does not seem to develop a great tolerance to the effects of caffeine although dependence and withdrawal symptoms are reported.
Author(s): Majithia N
Author(s): Evans JC
Author(s): Bolton S, Null G
Author(s): Cano-Marquina A, Tarín JJ, Cano A
Author(s): Qi H, Li S
Author(s): Ding M, Bhupathiraju SN, Satija A, van Dam RM, Hu FB
Author(s): Juliano LM, Griffiths RR
Author(s): Robertson D, Wade D, Workman R, Woosley RL, Oateshttp JA
Author(s): Frary CD, Johnson RK, Wang MQ
Author(s): Barone JJ, Roberts HR
Author(s): Winston AP, Hardwick E, Jaberi N
Author(s): Verkhratsky A
Author(s): Holmgren P, Nordén-Pettersson L, Ahlner J
Author(s): Rodopoulos N, Wisén O, Norman A
Author(s): Uddin MS, Wali MW, Mamun AA, Asaduzzaman M, Amran MS, et al.
Author(s): Liguori A, Hughes JR, Grass JA
Author(s): James JE
Author(s): Vanderveen JE, Armstrong LE, Butterfield GE, Chenoweth WL, Dwyer JT, et al.
Author(s): Parsons WD, Neims AH
Author(s): Aranda JV, Cook CE, Gorman W, Collinge JM, Loughnan PM, et al.
Author(s): Aranda JV, Sitar DS, Parsons WD, Loughnan PM, Neims AH
Author(s): Finnegan D
Author(s): Coelho A, Fraichard S, Le Goff G, Faure P, Artur Y, Ferveur JF, Heydel JM
Author(s): Verbeeck RK
Author(s): Borycz J, Pereira MF, Melani A, Rodrigues RJ, Kofalvi A, et al.
Author(s): Baker WJ, Theologus GC
Author(s): Bolton S, Null G
Author(s): Chen JF, Chern Y
Author(s): Camilo O, Goldstein LB
Author(s): Yadav S, Gupta SP, Srivastava G, Srivastava PK, Singh MP
Author(s): Salvemini D, Kim SF, Mollace V
Author(s): Federico S, Spalluto G
Author(s): Chu YF, Chang WH, Black RM, Liu JR, Sompol P, et al.
Author(s): Sonsalla PK, Wong LY, Harris SL
Author(s): Palacios N, Gao X, McCullough ML
Author(s): Chen X, Ghribi O, Geiger JD
Author(s): Prasanthi JR, Dasari B, Marwarha G