P21 (Adamantane) 10mg

CNTF (ciliary neurotrophic factor) is a neuroprotective cytokine that signals through a receptor complex including CNTF receptor alpha (CNTFRalpha), LIF receptor beta, and gp130. It supports the survival of multiple neuron types, promotes adult neurogenesis, and has anti-inflammatory CNS effects. P21 is derived from CNTF's binding domain with the CNTFRalpha subunit -- it retains the ability to activate CNTFRalpha signaling without the full CNTF protein. This is useful because full CNTF has poor CNS penetration and systemic side effects (fever, weight loss) that P21 may avoid by its smaller size and targeted signaling.

Adult hippocampal neurogenesis is the ongoing generation of new neurons in the dentate gyrus of the hippocampus in adult mammals. These new neurons integrate into existing circuits and appear to play roles in pattern separation, memory encoding, and mood regulation. Neurogenesis rates decline substantially with aging and stress, and many interventions that improve cognitive aging in rodents (exercise, caloric restriction, enriched environment) also stimulate neurogenesis. P21's neurogenic effects in aging rodent models are in the context of this literature -- whether restored neurogenesis mediates cognitive improvements is an active research question.

Adamantane is a cage-like carbon structure that is highly lipophilic. Attaching it to peptides or small molecules increases their lipophilicity, which generally improves blood-brain barrier penetration (the BBB preferentially allows lipophilic molecules to cross). For a CNS-targeted peptide like P21, improved BBB penetration means more compound reaches the target brain tissue after systemic administration. Adamantane modifications are used in several CNS drug development contexts for this purpose -- amantadine (an adamantane derivative) is itself a long-used CNS drug.