Introduction
Synaptic cell-adhesion molecules and their interactions with other molecular pathways affect both synapse formation and its function (Varoqueaux et al., 2006; Sudhof, 2008; Bemben et al., 2015a). Neurexins are presynaptic cell-adhesion molecules that interact with neuroligins and other postsynaptic partners. Neurexins are encoded by three genes, each of which encodes a long and short isoform, termed α- and β-neurexins, respectively (Sudhof, 2008). Interestingly, despite studies linking neurexins to autism and other neuropsychiatric disorders (Leone et al., 2010; Rabaneda et al., 2014), the precise cellular mechanisms underlying the role of neurexins in cognition remain poorly understood.

Since most biochemical studies of neurexins have focused on β-neurexins, investigating the synaptic actions of β-neurexins is particularly imperative. In their timely Cell article, Anderson et al. reported that β-neurexins selectively modulate synaptic strength at excitatory synapses by regulating postsynaptic endocannabinoid synthesis, describing an unexpected trans-synaptic mechanism for β-neurexins to control neural circuits via endocannabinoid signaling. 

Source: https://www.frontiersin.org/articles/10.3389/fnins.2016.00203/full

See also:

https://drugprevent.org.uk/ppp/2018/08/%CE%B2-neurexins-control-neural-circuits-by-regulating-synaptic-endocannabinoid-signaling/