TY - JOUR
T1 - Central connections of the ovine olfactory bulb formation identified using wheat germ agglutinin-conjugated horseradish peroxidase
AU - Jansen, Heiko T.
AU - Iwamoto, Gary A.
AU - Jackson, Gary L.
N1 - Funding Information:
This work was supported by USPHS grant HD13037.
PY - 1998
Y1 - 1998
N2 - Pheromonal stimuli elicit rapid behavioral and reproductive endocrine changes in the ewe. The neural pathways responsible for these effects in sheep are unknown, in part, because the olfactory bulb projections have not been examined in this species. Using the anterograde and retrograde neuronal tracer, wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), we describe the afferent and efferent olfactory bulb connections of the Suffolk ewe. Injections of WGA-HRP limited to the main olfactory bulb resulted in retrograde labeling of cells in numerous telencephalic, diencephalic, and metencephalic regions. Terminal labeling was limited to layer la of ipsilateral cortical structures extending rostrally from the anterior olfactory nucleus (AON), piriform cortex, anterior-, and posterolateral- cortical amygdaloid nuclei to lateral entorhinal cortex caudally. Injections involving the accessory olfactory bulb and AON produced additional labeling of calls within the bed nucleus of the stria terminalis (BNST), medial nucleus of the amygdala, and a few cells in the posteromedial cortical nucleus of the amygdala. Terminal labeling included a small dorsomedial quadrant of BNST and also extended to the far lateral portions of the supraoptic nucleus. A clearly defined accessory olfactory tract and nucleus was not evident, perhaps due to limitations in the sensitivity of the method. With this possible exception, the afferent and efferent olfactory connections in the sheep appear similar to those reported for other species.
AB - Pheromonal stimuli elicit rapid behavioral and reproductive endocrine changes in the ewe. The neural pathways responsible for these effects in sheep are unknown, in part, because the olfactory bulb projections have not been examined in this species. Using the anterograde and retrograde neuronal tracer, wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP), we describe the afferent and efferent olfactory bulb connections of the Suffolk ewe. Injections of WGA-HRP limited to the main olfactory bulb resulted in retrograde labeling of cells in numerous telencephalic, diencephalic, and metencephalic regions. Terminal labeling was limited to layer la of ipsilateral cortical structures extending rostrally from the anterior olfactory nucleus (AON), piriform cortex, anterior-, and posterolateral- cortical amygdaloid nuclei to lateral entorhinal cortex caudally. Injections involving the accessory olfactory bulb and AON produced additional labeling of calls within the bed nucleus of the stria terminalis (BNST), medial nucleus of the amygdala, and a few cells in the posteromedial cortical nucleus of the amygdala. Terminal labeling included a small dorsomedial quadrant of BNST and also extended to the far lateral portions of the supraoptic nucleus. A clearly defined accessory olfactory tract and nucleus was not evident, perhaps due to limitations in the sensitivity of the method. With this possible exception, the afferent and efferent olfactory connections in the sheep appear similar to those reported for other species.
KW - Neural tract-tracing
KW - Olfactory bulb
KW - Reproduction
KW - Sheep
KW - WGA-HRP
UR - http://www.scopus.com/inward/record.url?scp=0031975187&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031975187&partnerID=8YFLogxK
U2 - 10.1016/S0361-9230(97)00279-7
DO - 10.1016/S0361-9230(97)00279-7
M3 - Article
C2 - 9434199
AN - SCOPUS:0031975187
SN - 0361-9230
VL - 45
SP - 27
EP - 39
JO - Brain Research Bulletin
JF - Brain Research Bulletin
IS - 1
ER -