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.
Definition of tinfoil hat. metaphorically, a hat made of tinfoil that people who subscribe to conspiracy theories wear, to prevent electromagnetic signals from being beamed into their brain.NASA just made an announcement that they've found no evidence of life on Mars. Break out the tonfoil hats.