Unlike an electrical synapse, the chemical synapses are separated by a space called the synaptic cleft, typically measured between 15 and 25 nm. Transmission of an excitatory signal involves several steps outlined below.
Definition of cap. 1  1a : a head covering especially with a visor and no brimb : a distinctive head covering emblematic of a position or office: such as (1) : a cardinal's biretta (2) : mortarboard.
The noun HAT has 2 senses: 1. headdress that protects the head from bad weather; has shaped crown and usually a brim. 2. an informal term for a person's role. Familiarity information: HAT used as a noun is rare.