Neurotransmitters are chemical messengers that coordinate the transmission of signals from one nerve cell (neuron) to the next.eurotransmitters are chemical messengers that coordinate the transmission of signals from one nerve cell (neuron) to the next.
Soldiers in the secondary zone may be boarded with 16 months time-in-service and four months time-in-grade as of the first day of the board month. The time-in-service requirement for attaining eligibility for promotion to SSG is 84 months Active Federal Service for the primary zone and 48 months for the secondary zone.
The Secondary Zone is a shortened timeline applicable to soldiers whose service and leadership qualities are outstanding. To appear before the board for the role of Sergeant, the Primary Zone timeline is 34 months in service and six months as an E4, with the actual promotion taking place no earlier than at 36 months in service and eight months in rank.