Table 4.
Preclinical studies comparing the effects of adolescent and adult cannabinoid exposure.
| Study | Task/Testing | Adolescent Age of Exposure | Adult Age of Exposure | Washout Period | Animal Type | Drug Used | Results |
|---|---|---|---|---|---|---|---|
| Cha et al. (99) | Water Maze - Spacial task | 34/36-55/57 PND | 69/74-80/85 PND | 28 days | Sprague Dawley rats | THC | No effect of drug was seen between groups |
| Water Maze - Non-Spacial Task | 34/36-55/57 PND | 69/74-80.85 PND | 28 days | Sprague Dawley rats | THC | No effect of drug was seen between groups | |
| Cha et al. (100) | Water Maze | 30-51PND | 70-91PND | 28 days | Sprague Dawley rats | THC | No effect of drug was seen between groups |
| Gleason et al. (101) | Prepulse inhibition | 30-35 PND | 63-70 PND | 120 PND | Mice | WIN 55,212-2 | Adolescence treated animals had deficits in inhibition compared to control animals. No deficit seen in adult treated animals compared to control animals. |
| Fear Conditioning | 30-35 PND | 63-70 PND | 120 PND | Mice | WIN 55,212-2 | Adolescent animals had deficits in contextual learning compared to control animals. No deficits seen in adult treated animals compared to control animals. | |
| Harte and Dow-Edwards (102) | Active Place Avoidance Testing | 22-40 PND | 41-60 PND | Adolescence: 33 days Adults: 16 days |
Sprague Dawley rats | THC | Adolescent treated animals performed worse compared to control animals. No significant difference between adults and control animals. |
| Kasten et al. (103) | Object Recognition | 35-44 PND | 76-85 PND | Adolescent: 71 PND Adults: 117 PND |
Mice | THC | No effect of drug was seen between groups |
| CB1 receptor expression | 35-44 PND | 76-85 PND | Adolescent: 71 PND Adults: 117 PND |
Mice | THC | Adolescent treated animals maintained increased CB1 receptor expression | |
| O’Shea et al. (104) | Object Recognition | 30-51 PND | 56-77 PND | 21 days | Wister rat | CP55,940 | Adolescent treated animals had significantly poorer performance than adult treated animals |
| O’Shea et al. (105) | Object Recognition | 30 -51 PND | 56 -77 PND | 28 days | Wister rat | CP55,940 | No significant difference in either group |
| Social Interaction Test | 30 -51 PND | 56 -77 PND | 28 days | Wister rat | CP55,940 | Adolescent treated animals had increased anxiety. No significant difference in adult treated animals. | |
| Quinn et al. (106) | Object Recognition | 28 PND | 60 PND | 10 – 15 days | Wister rat | THC | Adolescent treated animals had significantly impaired object recognition. |
| Renard et al. (107) | Object Recognition | 29-50 PND | 70-91 PND | 28 days | Wister rat | CP55,940 | Drug treated animals spent less time exploring novel objects and had significantly different times exploring familiar objects to control. No significant difference seen between adult animals and control group. |
| 29-50 PND | 70-91PND | 28 days | Lister Hooded rat | CP55,940 | Drug treated animals spent less time exploring novel objects and had significantly different times exploring familiar objects to control. No significant difference seen between adult animals and control group. | ||
| Object location | 29-50 PND | 70-91PND | 28 days | Wister rat | CP55,940 | Drug treated animals did not show a significant change to novel exploration time, where control did. No significant difference seen between adult animals and control group. | |
| 29-50 PND | 70-91PND | 28 days | Lister Hooded rat | CP55,940 | Drug treated animals did not show a significant change to novel exploration time, where control did. No significant difference seen between adult animals and control group. | ||
| Schneider and Koch (108) | Object Recognition | 40-65 PND | > 70 PND | 20-25 days | Wister rat | WIN55,212-2 | Drug treated animals showed significantly impairment of recognition memory. No significant difference between adults and controls. |
| Novel object recognition was significantly lower in drug treated animals to controls, however delay time had no significant effect between groups. No significant effect between adults and controls. | |||||||
| Dalton and Zavitsanou (109) | Acute CP55,940 Treatment |
35 PND | 24 hrs | Wister rat | HU210 | Adolescent treated animals had a reduction in compensatory downregulation of CB1 receptors | |
| Higuera-Matas et al. (110) | Hippocampal Microdialysis Testing | 28 – 38 PND | 93 – 96 PND | Wister rat | CP 55,940 | Drug treated animals had increased GABA release in the hippocampus and increased GABA receptor expression | |
| Renard et al. (111) | Electrophysiological analyses | 35 PND | 30 days | Sprague-Dawley rat | THC | Drug treated animals had decreased GABAergic levels in PFC compared to controls animals | |
| Rubino et al. (112) | Hippocampal protein expression and binding analysis | 35-45 PND | 30 days | Sprague Dawley rats | THC | Drug treated animals had reduced VAMP2 expression and NMD receptor binging in the hippocampus | |
| Rubino et al. (113) | Histochemical analysis | 35 – 45 PND | 1, 15 or 30 days | Sprague-Dawley rat | THC | Drug treated animals had decreased expression and sensitivity of CB1 Receptors and increased levels of NMDA receptors | |
| Verdurand et al. (114) | [35S]t-butylbicyclophosphorothionate autoradiography | 5 weeks | 10 weeks | 24 hours | Wister rat | HU210 | Cannabinoid exposed rats had increased hippocampal binding. No significant effects of GABA receptors |
| Zamberletti et al. (115) | Histochemical analysis | 35-45 PND | 30 days | Sprague-Dawley rats | THC | Reduced levels of GABA in the PFC |
CB1 receptor, cannabinoid receptor type 1; THC, delta-9-Tetrahydrocannabinol; GABA, gamma-aminobutyric acid; PFC, pre-frontal cortex; NMDA, N-methyl-d-aspartate; VAMP2, vesicle-associated membrane protein 2.