Current studies suggest a role of the medial habenula (MHb) and interpeduncular nucleus (IPN) in stress, anxiety, depression and addiction. These regions were found to have increased glucose intake during anesthesia (Herkenham, 1981), and MHb has the densest μ-opioid receptors (MORs) in the brain (Gardon and Faget, 2014). The MHb-IPN pathway is enriched in nicotinic acetylcholine receptor (nAChR) and influences the brain response to nicotine (Antolin-Fontes et al., 2014). Theoretical work (Vadovičová, 2015) showed how the MHb→IPN→MRN circuit activates serotonin release and inhibits the theta states, arousal, alert wakefulness, awareness and REM sleep linked circuits. Study proposed that MHb activates IPN which activates MRN that promotes rest, slow wave sleep (SWS), slow wave oscillations, recovery, hippocampo-cortical replay of temporaly, spatialy and relationally bound memories, sharp wave ripples, cortical spindles, synaptogenesis and BDNF linked growth (Vadovičová, 2015). This paper will show how the stress, danger, worries and safety interact with the MHb-IPN circuit. It will show new neural mechanism for loss of awareness and memory replay, anesthesia, respiratory slowdown, opiates induced respiratory depression OIRD (circuit underneath the opiate crisis) and sudden infant death syndrome SIDS. This study will link claustrum and cortex to the hippocampus →posterior septum →MHb →IPN →MRN circuit.
