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Medial preoptic circuit induces hunting-like actions to target objects and prey

Nature Neurosciencevolume 21pages364372 (2018) | Download Citation


As animals forage, they must obtain useful targets by orchestrating appropriate actions that range from searching to chasing, biting and carrying. Here, we reveal that neurons positive for the α subunit of Ca2+/calmodulin-dependent kinase II (CaMKIIα) in the medial preoptic area (MPA) that send projections to the ventral periaqueductal gray (vPAG) mediate these target-directed actions in mice. During photostimulation of the MPA–vPAG circuit, mice vigorously engaged with 3D objects and chased moving objects. When exposed to a cricket, they hunted down the prey and bit it to kill. By applying a head-mounted object control with timely photostimulation of the MPA–vPAG circuit, we found that MPA–vPAG circuit-induced actions occurred only when the target was detected within the binocular visual field. Using this device, we successfully guided mice to navigate specified routes. Our study explains how the brain yields a strong motivation to acquire a target object along the continuum of hunting behavior.

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Change history

  • Correction 07 March 2018

    In the version of this article initially published, a sentence in the fifth paragraph of the Results read, “Immunohistochemistry revealed that VGLUT2+ MPA neurons rarely expressed CaMKIIα, which is a putative marker for subcortical glutamatergic neurons.” It should have read, “Immunohistochemistry revealed that CaMKIIα+ MPA neurons rarely expressed VGLUT2, which is a putative marker for subcortical glutamatergic neurons.” The error has been corrected in the HTML and PDF versions of the article. In the supplementary information originally posted online, the wrong version of Supplementary Fig. 1 was posted and some of the supplementary videos were interchanged. In the corrected Supplementary Fig. 1, the top right subpanel was added and the original Supplementary Fig. 1a was divided into 1a and 1b, with subsequent panels incremented accordingly. The legend was changed from “a. Schematic illustrating electrical lesioning of the rat anterior hypothalamus. Electrical lesion areas (gray) in five representative brain sections are depicted. Scale bar, 1 mm” to “a. Repetitive electrical stimulations of the anterior hypothalamus using bipolar electrodes (Left) caused a lesion at the hypothalamic area (middle, marked by asterisk) successfully in 7 rats (Right, overlapped images of brain sections located from the bregma −0.24 mm). Scale bar, 1 mm. b. Electrical lesion areas (gray) in five representative brain sections from anterior to posterior are depicted.” The errors have been corrected online.


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We thank K. Deisseroth at Stanford University for generously sharing the channelrhodopsin vectors and Y-S. Jeong, J-E. Choi and M-K. Han for their assistance with experiments. We also thank to S. Park for assistance with writing. This work was supported by Samsung Science and Technology Foundation under Project Number SSTF-BA1301-07.

Author information

Author notes

  1. These authors contributed equally: Sae-Geun Park, Yong-Cheol Jeong and Dae-Gun Kim.


  1. Department of Biological Sciences, KAIST, Daejeon, Korea

    • Sae-Geun Park
    • , Yong-Cheol Jeong
    • , Dae-Gun Kim
    • , Min-Hyung Lee
    • , Anna Shin
    • , Geunhong Park
    • , Jia Ryoo
    • , Jiso Hong
    • , Seohui Bae
    •  & Daesoo Kim
  2. Department of Mechanical Engineering, KAIST, Daejeon, Korea

    • Dae-Gun Kim
    • , Cheol-Hu Kim
    •  & Phill-Seung Lee


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D.K. and P.-S.L. designed the study and coordinated the experiments. S.-G.P., Y.-C.J., G.P. and S.B. performed the behavioral experiments with optogenetics. D.-G.K., C.-H.K., P-S.L. and Y.-C.J. developed the head-mounted device, MIDAS algorithm and navigation platform. Y.-C.J. and A.S. performed the electrophysiological experiments. M.-H.L., J.R. and J.H. performed the histological experiments and analysis. All authors participated in writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Phill-Seung Lee or Daesoo Kim.

Integrated supplementary information

  1. Supplementary Figure 1 Electrical lesions of the anterior hypothalamus abolish object-hoarding behavior in Long Evans rats.

    a. Schematic illustrating electrical lesioning of the rat anterior hypothalamus. Electrical lesion areas (gray) in five representative brain sections are depicted. Scale bar, 1 mm. b. Schematic depiction of the hoarding behavior experimental protocol. c. Latency to hoard in sham and lesion groups. The lesion group showed a significant object hoarding delay (Sham, n = 8 rats, Lesion, n = 7 rats; Mann Whitney U test, P = 0.021). d. Total play-like object engagement was significantly reduced in the lesion group (Sham, n = 8 rats, Lesion, n = 7 rats; Unpaired t-test, P = 0.49). Bar graphs indicate mean (bars) ± SEM (error bars) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

  2. Supplementary Figure 2 Immunohistochemical analysis of cFos activity in hypothalamic nuclei upon object exposure.

    a. Representative immunohistochemistry (IHC, stained with DAB) images of cFos expression in the MPA. Scale bars, 200 µm. b. Magnified images (control, n = 8 mice; object; n = 7 mice). Scale bars, 50 µm. c. Representative images from other hypothalamic regions (control, n = 8 mice; object, n = 7 mice). Scale bars, 100 µm. Abbreviations: LPO, lateral preoptic area; VLPO, ventrolateral preoptic nucleus; vBNST, ventral bed nucleus of the stria terminalis; SHy, septohypothalamic nucleus; PVN, paraventricular nucleus; VMH, ventromedial hypothalamus; Arc, arcuate nucleus; aca, anterior commissure (anterior part). See Figure 1b for the quantitative data

  3. Supplementary Figure 3 Validation of virally mediated expression of ChR2 in VGLUT2::ChR2MPA-vPAG and VGAT::ChR2MPA-vPAG mice.

    a. Top, Schematic depiction of VGLUT2+ MPA-vPAG circuit photostimulation of VGLUT2-ires-Cre mice. Bottom, Representative images of virally mediated ChR2 expression in the MPA and its termini in vPAG. 5 mice were used for these images. b. Top, Schematic illustration of photostimulation in VGAT-ires-Cre mice. Bottom, Representative images of ChR2 expression in MPA and vPAG of VGAT-ires-Cre mice. 5 mice were used for these images. Scale bars, 200 µm

  4. Supplementary Figure 4 Appropriate expression of ChR2 in the MPA and the effective location of fiber optic fiber in the PAG.

    a. Representative image of virally mediated ChR2 expression in the MPA and surrounding brain regions. b. Representative image of an individual mouse brain showing non-specific viral expression leading to reduced MPA-specific expression. Note that this mouse showed no response to objects during photostimulation. c. Quantification of viral expression in the MPA and surrounding brain regions (n = 17 mice; RM ANOVA on Ranks, MPA vs. LPO, P < 0.05; MPA vs. VLPO, P < 0.05; MPA vs. vBNST, P < 0.05; MPA vs. SHy, P < 0.05). d. Schematic depiction of retrograde tracing from vPAG. Bottom, Representative image of the MPA and surrounding brain regions. Note that labeled neurons project to the vPAG. e. Representative image of retrograde tracing. 3 mice were used for this image. f. Quantification of labeled neurons in the MPA and surrounding brain regions (n = 3 mice; One Way RM ANOVA, MPA vs. LPO, P = 0.002; MPA vs. VLPO, P = 0.001; MPA vs. vBNST, P = 0.001; MPA vs. SHy, P = 0.002). g. Locations of the fiber optic cannulas in the vPAG. The red crosses indicate the optic fiber tip locations in mice that responded to an object (n = 6) during photostimulation of the MPA-vPAG circuit; the black crosses indicate tip locations in mice that showed no response (n = 3). Scale bars, 200 µm. Bar graphs indicate mean (bars) ± SEM (error bars) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

  5. Supplementary Figure 5 Photostimulation of somata and axon termini of CaMKIIα+ MPA neurons.

    a. Photostimulation of MPA neuron somata increases object dislocation by CaMKIIα::ChR2MPA mice (n = 6) more than control eYFPMPA mice (n = 7; Mann Whitney U test, Light on state between two groups, P = 0.008; Wilcoxon Signed Rank test, ON vs. OFF in ChR2, P = 0.031). b. Female CaMKIIα::ChR2MPA-vPAG mice (red lines; n = 4) moved presented objects more during photostimulation than control CaMKIIα::eYFPMPA-vPAG mice (gray lines; n = 5; Two Way RM ANOVA, ON state between two groups, P < 0.001; OFF vs. ON in ChR2, P < 0.001; ON vs. OFF in ChR2, P < 0.001). c. Bar graphs comparing object dislocation during photostimulation of CaMKIIα MPA somata in male mice and of the CaMKIIα MPA-vPAG circuit in male and female mice (n = 7 mice for MPA somata, n = 5 for CaMKIIα::ChR2MAP-vPAG male mice, n = 4 for CaMKIIα::ChR2MAP-vPAG female mice; One Way ANOVA, MPA somata vs. CaMKIIα::ChR2MAP-vPAG male, P < 0.001; CaMKIIα::ChR2MAP-vPAG male vs. CaMKIIα::ChR2MAP-vPAG female, P = 0.004). Line graphs represent mean (thick lines) ± SEM (error bars) and individual data (brighter lines). Bar graphs indicate mean (bars) ± SEM (error bars) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

  6. Supplementary Figure 6 Attention shift to objects from females in the CaMKIIα::ChR2MPA-vPAG mice.

    a. Photostimulation elevates the locomotion of CaMKIIα::ChR2MPA-vPAG (n = 8) mice but not in CaMKIIα::eYFPMPA-vPAG (n = 5) mice (Unpaired t-test, P = 0.008). b. Representative behavioral raster plots for the inter-male aggression test. Each behavior is color-coded as indicated. 6 mice were used for this image. c. Percentage of social exploration and attacks versus non-social exploration behaviors (i.e., searching and digging) during encounters with an intruder male. Note that photostimulation reduced attacks toward the intruder male and increased non-social exploration. Photostimulation did not alter social exploration behavior (n = 6 for CaMKIIα::ChR2MPA-vPAG mice, Paired t-test, social exploration, P = 0.308; attack, P = 0.003; non-social exploration, P = 0.007). Colored-boxes represent percentage of each behaviors. d. Duration of attacks by CaMKIIα::eYFPMPA-vPAG (n = 6) and CaMKIIα::ChR2MPA-vPAG (n = 6) mice (Mann Whitney U test, P = 0.026). e. Number of attacks by CaMKIIα::eYFPMPA-vPAG (n = 6) and CaMKIIα::ChR2MPA-vPAG (n = 6) mice (Unpaired t-test, P = 0.037). f. Percentage of time male CaMKIIα::ChR2MPA-vPAG (n = 10) and CaMKIIα::eYFPMPA-vPAG (n = 8) mice (Unpaired t-test, P = 0.00000415) spent searching for females during photostimulation. Note that, like what we observed in the inter-male aggression tests, CaMKIIα::ChR2MPA-vPAG mice spent less time searching because they spent more time in non-social exploration. g. CaMKIIα::ChR2MPA-vPAG (n = 6) eat less than CaMKIIα::eYFPMPA-vPAG (n = 8) mice during photostimulation (Unpaired t-test, P = 0.001). Bar graphs show mean (bars) ± SEM (error bars) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

  7. Supplementary Figure 7. In vivo activity of the CaMKIIα+ MPA–vPAG circuit measured by photometry.

    a. The expression of GCAMP6m that mediated by viral infection of AAV9-CAG-DIO-GCaMP6m and AAV5-CaMKIIα::-Cre in MPA. 6 mice were used for these images. Scale bars, 200 µm. b. Representative raw trace of fluorescent activity [ΔFF= ( F - F m e a n ) F m e a n ] during object exploration. c. Success rates, which indicate increase of fluorescent activity during object exploration, are not different across the bouts. (n = 6 mice; One Way RM ANOVA, P = 0.800) Bar indicate average of population and colored-lines indicate individuals. d. Peak fluorescent activity of individuals runs down across the bout number. (n = 6 mice) Bar graphs indicate mean (bars) ± SEM (error bars) and individual data (colored-lines). Dot graphs represent mean (dots) ± SEM (error bars), trend line (green line) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

  8. Supplementary Figure 8. Photoinhibition of the CaMKIIα+ MPA–vPAG circuit abolishes object exploration.

    a. Left, CaMKIIα::eNpHR3.0MPA-vPAG mice (n = 8) move presented objects less than control CaMKIIα::eYFPMPA-vPAG mice (n = 5, Two Way RM ANOVA, 5 min, P < 0.01; 10 min P = 0.135; 15 min, P = 0.643; 20 min, P = 0.562). Line graph indicates mean (lines) ± SEM (error bars). Right, Curves for individual mice. b. Total food intake. CaMKIIα::eYFPMPA-vPAG (n = 5) and CaMKIIα::eNpHR3.0MPA-vPAG (n = 6) mice (Unpaired t-test, P = 0.936) eat similar amounts. Bar graphs represent mean (bars) ± SEM (error bars) and individual data (colored-lines). See the detailed statistical values in Supplementary table 1. * P < 0.05, n.s. not significant

  9. Supplementary Figure 9 The hardware configuration of the MIDAS.

    a. Photographs of the head-mounted device components and Bluetooth module. Scale bar, 1 cm. b. Schematic for the overall system. The PC navigation program analyzes positional information for each mouse and for the 3D maze using a CMOS camera. It then transmits control commands to the head-mounted device via Bluetooth. The controller chipset in the head-mounted device controls the target object servomotor and the LED module. c. The average mouse velocity in response to photostimulation using different LED-ON angles (n = 5 mice; One Way RM ANOVA, 30° vs. 10°, P = 0.023; 30° vs. 40°, P = 0.039; 30° vs. 70°, P = 0.013). d. The average velocity from the start to the goal as a function of frequency (n = 3 mice; One Way RM ANOVA, 0 Hz vs. 40 Hz, P < 0.001; 10 Hz vs. 40 Hz, P < 0.001; 15 Hz vs. 40 Hz, P < 0.001; 20 Hz vs. 40 Hz, P = 0.008). Line graphs represent mean (thick lines) ± SEM (error bars) and individual data (brighter lines). See the detailed statistical values in Supplementary table 1. * P < 0.05

  10. Supplementary Figure 10 A complex maze for evaluating the control of mouse behavior by MIDAS.

    a. The maze consists of seven hurdles: a zig-zag course; a female distractor; blind alleys; rough terrain; a mesh ladder; food distractors; and a bridge. b. Latency to the goal during a 300-s navigation session. Note that the OC+ LC condition showed significantly less latency than the other conditions (n = 5 mice; One Way RM ANOVA, OC only vs. OC+LC, P < 0.001; LC only vs. OC+LC, P < 0.001). c. Frequency of getting trapped in the hurdles, quantified as described in the Methods. Note that mice in the OC+LC condition were trapped in the hurdles significantly less often than mice of the other conditions (n = 5 mice; One Way RM ANOVA, OC only vs. OC+LC, P = 0.009; LC only vs. OC+LC, P = 0.008). Bar graphs indicate mean (bars) ± SEM (error bars) and individual data (circles). See the detailed statistical values in Supplementary table 1. * P < 0.05

Supplementary information


  1. Supplementary Video 1:

    Time-dependent responses of mice toward objects. A light cube was provided to a B6 mouse. Before habituation, the mouse showed awareness of the light cube. With time, the mouse began to show active engagement, such as touching, biting and, in the late phase, dislocation.

  2. Supplementary Video 2:

    Photostimulation of the CaMKIIα+ MPA–vPAG circuit induces strong object explorative behaviors. Photostimulation of the MPA–vPAG circuit (CaMKIIα::ChR2MPA-vPAG) induced a stronger object exploration compared with that observed in CaMKIIα::ChR2MPA and CaMKIIα::eYFPMPA-vPAG control mice.

  3. Supplementary Video 3:

    Photostimulation of CaMKIIα+ MPA neurons induces object explorative behaviors. Photostimulation of the MPA led to increased engagement with the presented object in a mouse transfected with ChR2 in the MPA (CaMKIIα::ChR2MPA) but not one transfected with control virus (CaMKIIα::eYFPMPA). Behavioral changes were evident between the light-OFF and light-ON states.

  4. Supplementary Video 4:

    In vivo calcium recording of the CaMKIIα+ MPA–vPAG circuit during object exploration. In vivo calcium recording was conducted in the vPAG to record signals from the axon termini of CaMKIIα+ MPA neurons expressing GCaMP6m. Note. The black bar located on the left side of the movie indicates ΔF/F in real-time. It turns red when the ΔF/F exceeds 3σ of the session.

  5. Supplementary Video 5:

    Photostimulation of male CaMKIIα::ChR2MPA-vPAG mice shifts their attention from a female to a target object. During the light-OFF state, a male CaMKIIα::ChR2MPA-vPAG mouse (C57BL/6J) spent more time searching for a female (BALB/cJ) than for a presented object. In the light-ON state, the male began to show more active engagement with the object rather than the female.

  6. Supplementary Video 6:

    Exploratory behaviors for various 3D objects in CaMKIIα::ChR2MPA-vPAG mice. Photostimulation of the CaMKIIα+ MPA–vPAG circuit led to object-specific manipulation that depended on the size and shape of the object. Objects examined included a ping-pong ball, cotton bud, wooden block and rubber cap. Video shows behavior during the light-ON state.

  7. Supplementary Video 7:

    Photostimulation of the CaMKIIα+ MPA–vPAG circuit triggers object-craving behaviors. Photostimulation of the MPA–vPAG circuit induces object-craving behaviors under various conditions. First, a CaMKIIα::ChR2MPA-vPAG mouse leaps down from a precipice to grasp the object. Second, a CaMKIIα::ChR2MPA-vPAG mouse jumps to grasp the object in the air, reaching out with its paws and mouth. Even when the object was presented above water, the mouse tried to catch it by moving around the edge of the water.

  8. Supplementary Video 8:

    Object-chasing behavior of CaMKIIα::ChR2MPA-vPAG mice toward a moving object. CaMKIIα::ChR2MPA-vPAG mice exposed to an object moving along the contours of the letters B and G (representing our Behavioral Genetics laboratory) followed the object during the light-ON state. When the light was turned off right before the mouse reached the letter G, the mouse stopped following the object and moved away from the G track.

  9. Supplementary Video 9:

    Photostimulation of the CaMKIIα+ MPA–vPAG circuit induces hunting-like actions to prey. CaMKIIα::ChR2MPA-vPAG mice exposed to a prey (cricket) under photostimulation. They showed series of hunting-like behaviors, such as chasing, biting and carrying.

  10. Supplementary Video 10:

    Steering of mouse navigation in a complex maze using the MIDAS system. The video shows a schematic overview of the complex maze and a CaMKIIα::ChR2MPA-vPAG mouse running the maze. Left, Top view of the maze (yellow circle, mouse; pink circle, object; black circle, waypoints; blue circle, current waypoint; red line, programmed pathway to the goal; blue line, current guiding direction; black line, actual track of the mouse). Top right, Close-up video of the maze. The names of the hurdles are shown. Bottom right, Actual mouse tracks and object positions, updated in real time (red circle, current object position). Note that the LED is turned on only when the object is positioned in the center of the five circles.

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