An anterograde degeneration study of the tangential spread of axons in cortical areas 17 and 18 of the squirrel monkey (Saimiri Sciureus)

1978 ◽  
Vol 179 (2) ◽  
pp. 245-262 ◽  
Author(s):  
M. Colonnier ◽  
E. Sas
Keyword(s):  
Squirrel Monkey ◽  
Saimiri Sciureus ◽  
Cortical Areas ◽  
Anterograde Degeneration ◽  
Areas 17 And 18 ◽  
Degeneration Study

Subcortical structures projecting to visual cortical areas in squirrel monkey

1982 ◽  
Vol 209 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Johannes Tigges ◽  
M. Tigges ◽  
N. A. Cross ◽  
R. L. McBride ◽  
W. D. Letbetter ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Subcortical Structures ◽  
Cortical Areas ◽  
Visual Cortical

Morphology and mitochondrial phylogenetics reveal that the Amazon River separates two eastern squirrel monkey species: Saimiri sciureus and S. collinsi

2015 ◽  
Vol 82 ◽  
pp. 426-435 ◽  
Author(s):  
Michelle P. Mercês ◽  
Jessica W. Lynch Alfaro ◽  
Wallax A.S. Ferreira ◽  
Maria L. Harada ◽  
José S. Silva Júnior
Keyword(s):  
Squirrel Monkey ◽  
Saimiri Sciureus ◽  
Amazon River ◽  
Monkey Species

Production of Zinc Deficiency in the Squirrel Monkey (Saimiri sciureus)

1967 ◽  
Vol 93 (4) ◽  
pp. 499-510 ◽  
Author(s):  
M. P. Macapinlac ◽  
G. H. Barney ◽  
W. N. Pearson ◽  
W. J. Darby
Keyword(s):  
Squirrel Monkey ◽  
Zinc Deficiency ◽  
Saimiri Sciureus

Terminal 13p deletion in squirrel monkey (Saimiri sciureus ) with differentiated phenotype

2018 ◽  
Vol 47 (6) ◽  
pp. 412-415
Author(s):  
B. Goldschmidt ◽  
C.A.A. Lopes ◽  
F. Resende ◽  
T.A. Pissinatti ◽  
D.C. Toledo ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Saimiri Sciureus

scholarly journals Sexual dimorphism in the squirrel monkey, Saimiri sciureus (Linnaeus, 1758) and Saimiri ustus (I. Geoffroy, 1844) (Primates, Cebidae)

2009 ◽  
Vol 69 (1) ◽  
pp. 171-174 ◽  
Author(s):  
B. Goldschmidt ◽  
A. Mota-Marinho ◽  
C. Araújo-Lopes ◽  
MA. Brück-Gonçalves ◽  
D. Matos-Fasano ◽  
...  
Keyword(s):  
Body Weight ◽  
Sexual Dimorphism ◽  
Squirrel Monkey ◽  
Coat Color ◽  
Morphological Characters ◽  
Saimiri Sciureus ◽  
External Ear ◽  
Adult Females ◽  
In The Wild ◽  
Capture Techniques

Causes and implications of sexual dimorphism have been studied in several different primates using a variety of morphological characters such as body weight, canine length, coat color and ornamentation. Here we describe a peculiar coat color characteristic in the squirrel monkey that is present only in adult females over five years old and which increases with age. Neither males nor young animals manifest this phenomenon, which is characterized by a spot of black hairs located anteriorly to the external ear (pinna). This characteristic could be used to discriminate adult females of Saimiri sciureus in the wild without the need of capture techniques.

Direct and Indirect Corticospinal Control of Arm and Hand Motoneurons in the Squirrel Monkey (Saimiri sciureus)

1997 ◽  
Vol 78 (2) ◽  
pp. 721-733 ◽  
Author(s):  
M. A. Maier ◽  
E. Olivier ◽  
S. N. Baker ◽  
P. A. Kirkwood ◽  
T. Morris ◽  
...  
Keyword(s):  
Squirrel Monkey ◽  
Macaque Monkey ◽  
Saimiri Sciureus ◽  
Excitatory Postsynaptic Potential ◽  
Onset Latency ◽  
Implanted Electrodes ◽  
Postsynaptic Potential ◽  
Common Response ◽  
Hand Muscle ◽  
Comparable Sample

Maier, M. A., E. Olivier, S. N. Baker, P. A. Kirkwood, T. Morris, and R. N. Lemon. Direct and indirect corticospinal control of arm and hand motoneurons in the squirrel monkey ( Saimiri sciureus). J. Neurophysiol. 78: 721–733, 1997. Anatomic evidence suggests that direct corticomotoneuronal (CM) projections to hand motoneurons in the New World squirrel monkey ( Saimiri sciureus) are weak or absent, but electrophysiological evidence is lacking. The nature of the corticospinal linkage to these motoneurons was therefore investigated first with the use of transcranial magnetic stimulation (TMS) of the motor cortex under ketamine sedation in five monkeys. TMS produced early responses in hand muscle electromyogram, but thresholds were high (compared with macaque monkey) and the onset latency was variable. Second, stimulation of the pyramidal tract (PT) was carried out with the use of chronically implanted electrodes in ketamine-sedated monkeys; this produced more robust responses that were markedly facilitated by repetitive stimulation, with little decrease in latency on the third compared with the first shock. Finally, postsynaptic potentials were recorded intracellularly from 93 arm and hand motoneurons in five monkeys under general chloralose anesthesia. After a single PT stimulus, the most common response was a small, slowly rising excitatory postsynaptic potential (EPSP), either alone (35 of 93 motoneurons) or followed by an inhibitory postsynaptic potential (39 of 93). The segmental delay of the early EPSPs was within the monosynaptic range (mean 0.85 ms); however, the rise time of these EPSPs was slow (mean 1.3 ms) and their amplitude was small (mean 0.74 mV). These values are significantly slower and smaller than EPSPs in a comparable sample of Old World macaque monkey motoneurons. The results show that CM connections do exist in the squirrel monkey but that they are weak and possibly located on the remote dendrites of the motoneurons. The findings are consistent with earlier anatomic studies. Repetitive PT stimulation produced large, late EPSPs in some motoneurons, suggesting that, in this species, there are relatively strong nonmonosynaptic pathways linking the corticospinal tract to hand motoneurons.

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