Neuronal synapse, artwork. Ink on paper painting of neuronal communication at a synapse. Neighboring neurones send information to each other through structures called synapses. The synapse consists of a presynaptic neurone (red; neurone sending the signal), the synaptic cleft (gap between the two neurones) and a postsynaptic neurone (blue; neurone receiving the signal). Neurones are cells in the nervous system which carry information in the form of electrical signals and allow us to sense and respond to our environment. Once an electrical signal reaches the synapse, chemical messengers (neurotransmitters; dots in the centre of the image) are released from the presynaptic neurone into the synaptic cleft. These travel across the synaptic cleft and are received by the postsynaptic neurone. Supplied by Stephen Magrath, courtesy of Wellcome Images.