In situ hybridization using isoform specific oligonucleotide probes to different exocytotic protein messenger RNAs ( mRNAs ) showed strong hybridization signal for synaptotagmin 1 , cysteine string protein ( CSP ) , VAMP 2 ( vesicle associated membrane protein ) , cellubrevin , munc 18 ( mammalian homologue of unc 18 ) , SNAP 25a ( synaptosomal associated protein of 25 kDa ) , syntaxin 1A , syntaxin 4 , syntaxin 5 , and alpha SNAP ( soluble NSF attachment protein ) in the anterior and intermediate , but not in the posterior lobe of the pituitary . ^^^ |