Unilateral lesions of the medial agranular cortex produce a persistent
disruption in the organization of food protection behaviors
S. J. WAGNER, M. J. HYLIN, M. M. MARTIN, S. S. WINTER, K. J. BURCHAM,
L. M. MCFADDEN, J. V. CORWIN, D. G. WALLACE
89.5/SS22
Dept Psychology, Northern Illinois Univ., DeKalb, IL, USA
Figure 7: Individual percentage of successful food protection behaviors are plotted for pre-testing, acute, and
Abstract
Results
Figure 2: Coronal sections stained with cresyl violet from representative control (left) and AGm (right) rats.
AGm lesions use the following coordinates: +5.0mm to -2.5 mm A.P. relative to bregma, 2.5mm from the midline.
Success food protection (%)
100
Methods
Figure 4: There were no group differences in the total
consumption times during pre-testing, acute, and
protracted testing.
food protection behaviors observed across pre-testing,
acute, and protracted testing.
Control
AGm
100
Total food protecion behaviors
100
80
60
40
20
Control
AGm
80
60
40
40
Control
AGm 2
AGm 3
AGm 7
AGm 11
20
w12
w10
w8
w6
Test w6-12
d1
d3
d5
d7
d9
d11
d13
d15
d17
Test d1-17
Figure 5: The robbers’ approaches were equally
Figure 6::There were no group differences observed
distributed across each side for both groups.
during pre-testing; however, rats with AGm lesions
were significantly less successful in protecting the
almond at acute and protracted testing.
Control
AGm
Overall success (%)
80
60
40
w6
w8
w10
w12
d1
d3
d5
d7
d9
d11
d13
d15
d17
p1
p2
w6
w8
w10
w12
d1
d3
d5
d7
d9
d11
d13
d15
d17
80
60
40
20
60
40
Test d1-17
Test w6-12
Pre-Testing
Test d1-17
Test w6-12
Conclusions
Rats that received AGm lesions had significant impairments in protecting the
Rats ate
t
R
food item from the robber relative to control
rats.
 This impairment was initially lateralized in the acute phase
 The impairment became bilateral at protracted time points
There were no differences in rates to consume the food items between groups
during pre-testing, acute and protracted time points.
 This implies the disruption in food protection was not mediated by
motivational factors
These results may suggest a role for the AGm in the organization of food
protection behavior, and they may represent a novel assessment technique for
therapeutic interventions related to deficits induced by stroke or
neurodegenerative disorders.
Acknowledgments: Bethany Barnes
20
Control
AGm
20
Correspondence:
w12
w10
w8
w6
d1
d3
d5
d7
d9
d11
d13
d15
d17
p1
p2
w12
0
w10
w8
w6
d1
d3
d5
d7
d9
d11
d13
d15
d17
0
p1
p2
Attempts on right side (%)
100
80
Control
AGm
Pre-Testing
20
p1
p2
Pre-Testing
100
0
0
0
100
Dodge
60
p1
p2
Figure 3: No group differences were found in rats’
Figure 1: Dodging behavior was video recorded from an angled mirror. Rats were placed
in the plastic cylinder (45 cm in diameter and 61cm in height) that was positioned on a
glass shelf (left photo). A digitized representation of a brace and a dodge is provided
(right illustration) in which the robber is characterized in red, and the dodger is in blue.
Brace
80
0
Consumtion time (sec)
Seven adult male Long-Evans rats, approximately 90 days old, were housed
in pairs and maintained at 90% of free feeding weight. Prior to testing, rats
were habituated to an arena and honey roasted almonds for one week. After
habituation, rats were tested to establish a baseline. During all sessions,
rats were given five trials (one almond/trial). For the first four trials, the
dodger consumed the food item in the presence of its cage mate (i.e., the
robber). If the food item was taken away by the robber, the experimenter
removed the robber from the arena, retrieved the food item, gave it back to
the dodger, and placed the robber back in the arena. During the fifth trial,
the time required to consume the almond in the absence of the robber was
measured after each session. Following pre-testing, rats were randomly
assigned to either an AGm aspiration lesion (n=4) or a control (n=3) group.
Several measures were used to quantify the organization of food protection
behaviors.
Right side
Left side
Successful protection of left side (%)
Rats use both external and internal sources of information to organize their
food protection behaviors. Although previous studies have demonstrated
that hemidecortication or cholinerergic deaffentation of the cortex disrupts
the ability to protect food from an approaching conspecific, as of yet, no
studies have examined the effects of more localized lesions. Past findings
have characterized the medial agranular cortex (AGm) as a multimodal
association area in rats that when damaged, produces deficits in orientation
behavior. The current study examined the contribution of the AGm to the
organization of food protection behavior.
protracted testing (top). Average percent food protection behaviors are plotted for each phase of testing (below).
AGm animals displayed a unilateral deficit during the acute testing phase which transitioned to a bilateral deficit
during the protracted phase.
Steve Wagner
sjwagner111@hotmail.com
J. V. Corwin
jcorwin@niu.edu
D.G. Wallace
dwallace@niu.edu
Web:
www.niu.edu/user/tj0dgw1