TY - JOUR
T1 - Comparison of bonobo and chimpanzee brain microstructure reveals differences in socio-emotional circuits
AU - Issa, Habon A.
AU - Staes, Nicky
AU - Diggs-Galligan, Sophia
AU - Stimpson, Cheryl D.
AU - Gendron-Fitzpatrick, Annette
AU - Taglialatela, Jared P.
AU - Hof, Patrick R.
AU - Hopkins, William D.
AU - Sherwood, Chet C.
N1 - Funding Information:
Acknowledgements The authors would like to thank Yerkes National Primate Research Center (supported by National Institutes for Health Grant ORIP/OD P51 OD011132), the National Chimpanzee Brain Resource (supported by National Institutes for Health Grant R24 NS092988-02), Milwaukee County Zoo, Jacksonville Zoo, and veterinary technicians for the donation of specimens. We would also like to thank Dr. Amy Bauernfeind for helpful discussion and Dr. John Allman for providing bonobo samples. This work was supported by the National Science Foundation (SMA-1542848) and the James S. McDonnell Foundation (220020293).
Funding Information:
The authors would like to thank Yerkes National Primate Research Center (supported by National Institutes for Health Grant ORIP/OD P51 OD011132), the National Chimpanzee Brain Resource (supported by National Institutes for Health Grant R24 NS092988-02), Milwaukee County Zoo, Jacksonville Zoo, and veterinary technicians for the donation of specimens. We would also like to thank Dr. Amy Bauernfeind for helpful discussion and Dr. John Allman for providing bonobo samples. This work was supported by the National Science Foundation (SMA-1542848)?and?the James S. McDonnell Foundation (220020293).
Publisher Copyright:
© 2018, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2019/1/15
Y1 - 2019/1/15
N2 - Despite being closely related, bonobos and chimpanzees exhibit several behavioral differences. For instance, studies indicate that chimpanzees are more aggressive, territorial, and risk-taking, while bonobos exhibit greater social tolerance and higher rates of socio-sexual interactions. To elucidate the potential neuroanatomical variation that accompanies these differences, we examined the microstructure of selected brain areas by quantifying the neuropil fraction, a measure of the relative tissue area occupied by structural elements of connectivity (e.g., dendrites, axons, and synapses) versus cell bodies. In bonobos and chimpanzees, we compared neuropil fractions in the nucleus accumbens (NAc; core and shell), amygdala (whole, accessory basal, basal, central and lateral nuclei), anterior cingulate cortex (ACC; dorsal and subgenual), anterior insular cortex (AIC), and primary motor cortex (M1). In the dorsal ACC and frontoinsular cortex (FI) we also quantified numbers of von Economo neurons (VENs), a unique subset of neurons thought to be involved in rapid information processing during social interactions. We predicted that the neuropil fraction and number of VENs in brain regions associated with socio-emotional processing would be higher in bonobos. In support of this hypothesis, we found that bonobos had significantly greater neuropil in the central and accessory basal nuclei of the amygdala, as well as layers V–VI of the subgenual ACC. However, we did not find a difference in the numbers of VENs between the two species. These findings support the conclusion that bonobo and chimpanzee brains differ in the anatomical organization of socio-emotional systems that may reflect species-specific variation in behavior.
AB - Despite being closely related, bonobos and chimpanzees exhibit several behavioral differences. For instance, studies indicate that chimpanzees are more aggressive, territorial, and risk-taking, while bonobos exhibit greater social tolerance and higher rates of socio-sexual interactions. To elucidate the potential neuroanatomical variation that accompanies these differences, we examined the microstructure of selected brain areas by quantifying the neuropil fraction, a measure of the relative tissue area occupied by structural elements of connectivity (e.g., dendrites, axons, and synapses) versus cell bodies. In bonobos and chimpanzees, we compared neuropil fractions in the nucleus accumbens (NAc; core and shell), amygdala (whole, accessory basal, basal, central and lateral nuclei), anterior cingulate cortex (ACC; dorsal and subgenual), anterior insular cortex (AIC), and primary motor cortex (M1). In the dorsal ACC and frontoinsular cortex (FI) we also quantified numbers of von Economo neurons (VENs), a unique subset of neurons thought to be involved in rapid information processing during social interactions. We predicted that the neuropil fraction and number of VENs in brain regions associated with socio-emotional processing would be higher in bonobos. In support of this hypothesis, we found that bonobos had significantly greater neuropil in the central and accessory basal nuclei of the amygdala, as well as layers V–VI of the subgenual ACC. However, we did not find a difference in the numbers of VENs between the two species. These findings support the conclusion that bonobo and chimpanzee brains differ in the anatomical organization of socio-emotional systems that may reflect species-specific variation in behavior.
KW - Amygdala
KW - Bonobo
KW - Chimpanzee
KW - Microstructure
KW - Neuropil
KW - Social cognition
KW - Von Economo neurons
UR - http://www.scopus.com/inward/record.url?scp=85055050519&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85055050519&partnerID=8YFLogxK
U2 - 10.1007/s00429-018-1751-9
DO - 10.1007/s00429-018-1751-9
M3 - Article
C2 - 30306256
AN - SCOPUS:85055050519
SN - 1863-2653
VL - 224
SP - 239
EP - 251
JO - Brain Structure and Function
JF - Brain Structure and Function
IS - 1
ER -