BACKGROUND:Studieshaveshownthatneurogenesisinthedentategyrusplaysanimportantroleinlearningandmemory.However,studieshavenotdeterminedwhetherthesuperiorcervicalganglionorthesympatheticnervesysteminfluenceshippocampalneurogenesisorlearningandmemoryinadultrats.OBJECTIVE:Toobservedifferencesindentategyrusneurogenesis,aswellaslearningandmemory,inadultratsfollowingsuperiorcervicalganglionectomy.DESIGN,TIMEANDSETTING:Arandomized,controlled,animalstudywasperformedattheImmunohistochemistryLaboratoryoftheSchoolofLifeSciencesinLanzhouUniversityfromJuly2006toJuly2007.MATERIALS:DoublecortinpolyclonalantibodywasprovidedbySantaCruzBiotechnology,USA;avidin-biotin-peroxidasecomplexwaspurchasedfromZhongshanGoldenbrideBiotechnology,China;MorriswatermazewasboughtfromTaimengTechnology,China.METHODS:Atotalof20adult,male,Wistarratswererandomlypidedintosurgeryandcontrolgroups,with10ratsineachgroup.Inthesurgerygroup,thebilateralsuperiorcervicalganglionsweretransected.Inthecontrolgroup,thesuperiorcervicalganglionswereonlyexposed,butnoganglionectomywasperformed.MAINOUTCOMEMEASURES:Toexaminedistribution,morphology,andnumberofnewbornneuronsinthedentategyrususingdoublecortinimmunohistochemistryat36daysfollowingsurgicalprocedures.ToexamineabilityoflearningandmemoryinadultratsusingtheMorriswatermazeat30daysfollowingsurgicalprocedures.RESULTS:Doublecortinimmunohistochemicalresultsshowedthatareductioninthenumberofdoublecortin-positiveneuronsinthesurgerygroupcomparedtothecontrolgroup(P<0.05),whilethedistributionofdoublecortin-positiveneuronswasidenticalinthetwogroups.Thesurgerygroupexhibitedsignificantlyworseperformanceinlearningandspatialmemorytaskscomparedtothecontrolgroup(P<0.05).CONCLUSION:Superiorcervicalganglionectomyinhibitedneurogenesisinthedentategyrusanddecreasedlearningandmemorya
