Ramírez-Lugo Leticia, Zavala-Vega Sergio, Pedroza-Llinas Rodrigo, Núñez-Jaramillo Luis, Bermúdez-Rattoni Federico
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, A.P. 70-253 México D.F., 04510, Mexico.
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, A.P. 70-253 México D.F., 04510, Mexico.
Behav Brain Res. 2015 May 1;284:213-7. doi: 10.1016/j.bbr.2015.02.020. Epub 2015 Feb 16.
Cortical glutamatergic activity is known to be important for memory formation in different learning tasks. For example, glutamate activity in the insular cortex plays an important role in aversive taste memory formation by signaling the unconditioned stimulus. However, the role of glutamate in the insular cortex in appetitive taste learning has remained poorly studied. Therefore, we considered the function of glutamate in attenuation of neophobia, a model of appetitive taste recognition memory. For this purpose, we performed infusions of vehicle, glutamate, a specific mGluR1 antagonist (AIDA) or a combination of glutamate and AIDA at 0 or 30 min, and glutamate or vehicle at 60 min after novel saccharin consumption. Glutamate infusion impaired appetitive taste recognition memory when infused at 0 or 30 min, whereas, AIDA infusions produced enhanced appetitive memory at the same infusion times. Furthermore, when glutamate and AIDA were infused together no effect on attenuation of neophobia was observed. As opposed to shorter infusion times, the administration of glutamate 60 min after the presentation of the saccharin consumption was ineffective in the impairment of the appetitive taste memory. These results are discussed in view of the effect of glutamate and its mGluR1 during the appetitive taste recognition memory formation in the insular cortex.
已知皮质谷氨酸能活动在不同学习任务的记忆形成中很重要。例如，岛叶皮质中的谷氨酸活动通过对非条件刺激发出信号，在厌恶性味觉记忆形成中发挥重要作用。然而，谷氨酸在岛叶皮质中对嗜好性味觉学习的作用仍研究不足。因此，我们考虑了谷氨酸在减轻新事物恐惧中的功能，新事物恐惧是一种嗜好性味觉识别记忆模型。为此，我们在摄入新型糖精后0或30分钟时，注入了溶媒、谷氨酸、一种特异性代谢型谷氨酸受体1拮抗剂（AIDA）或谷氨酸与AIDA的组合，并在60分钟时注入了谷氨酸或溶媒。在0或30分钟时注入谷氨酸会损害嗜好性味觉识别记忆，而在相同注入时间注入AIDA则会增强嗜好性记忆。此外，当谷氨酸和AIDA一起注入时，未观察到对减轻新事物恐惧有影响。与较短的注入时间相反，在呈现糖精摄入60分钟后给予谷氨酸对嗜好性味觉记忆的损害无效。鉴于谷氨酸及其代谢型谷氨酸受体1在岛叶皮质嗜好性味觉识别记忆形成过程中的作用，对这些结果进行了讨论。
