Acetylcholine is a neurotransmitter that plays an important role in

 The correct answer is :  in the brain and also works as a neuromodulator

Explanation:    Acetylcholine is a chemical released by a nerve cell or neuron. This neurotransmitter causes the muscles to contract, activates pain responses, regulates the endocrine and REM functions of sleep.

answer; the population in brazil is very diverse there are many races and ethnic groups

the arab empire adopted the muslim religion as their main belief. arabs would influence the people from the territories they invaded towards islam (the muslim belief).

nevertheless, throughout the history of the arab empire, rulers brought intellectual individuals from other religions to their centers of learning. these other foreigners included jews, christians, greeks, persians, and indians.   these resulted in the adoption of important knowledge developed by these cultures by the arabic empire. for example, the works of aristotle were translated from greek to arab and indian scientists brought the numerical concept of "zero" to the arabs.

nowadays, 93% of the arab population is muslim, which at the same time is subdivided in sects including the sunni, zaini, alawi, shia. the remaining 7% is composed mainly of christians.